Exhibit 4(b)(3)


               __________________________________________________




                            PUBLIC SERVICE COMPANY
                                  OF COLORADO


                                      TO


                           FIRST TRUST OF NEW YORK,
                             NATIONAL ASSOCIATION,

                                                       as Trustee


                                _________________



                         Supplemental Indenture No. 5

                         Dated as of November 1, 1996


                         Supplemental to the Indenture
                          dated as of October 1, 1993


                                ________________


                  Establishing the Securities of Series No. 4
                designated Secured Medium-Term Notes, Series B


               __________________________________________________

         






      SUPPLEMENTAL INDENTURE NO. 5, dated as of November 1, 1996, between PUBLIC
SERVICE COMPANY OF COLORADO, a corporation duly organized and existing under the
laws of the State of Colorado (hereinafter sometimes called the "Company"),  and
FIRST TRUST OF NEW YORK,  NATIONAL  ASSOCIATION,  a national banking association
(hereinafter  sometimes  called the "Trustee"),  as successor  trustee to Morgan
Guaranty Trust Company of New York under the  Indenture,  dated as of October 1,
1993 (hereinafter called the "Original Indenture"),  as previously  supplemented
and as further  supplemented by this Supplemental  Indenture No. 5. The Original
Indenture and any and all indentures and other instruments  supplemental thereto
are hereinafter sometimes collectively called the "Indenture".

                            Recitals of the Company

      The Original  Indenture  was  authorized,  executed  and  delivered by the
Company to provide for the issuance  from time to time of its  Securities  (such
term and all other capitalized  terms used herein without  definition having the
meanings  assigned to them in the  Original  Indenture),  to be issued in one or
more series as contemplated  therein, and to provide security for the payment of
the principal of and premium, if any, and interest, if any, on the Securities.

      The Company  has  heretofore  executed  and  delivered  to the Trustee the
Supplemental  Indentures  referred  to in  Schedule A hereto for the  purpose of
establishing various series of bonds and of appointing the successor trustee.

      The Company  desires to establish a series of  Securities to be designated
"Secured Medium- Term Notes, Series B", being a series of First Collateral Trust
Bonds, such series of Securities to be hereinafter  sometimes called "Series No.
4".

     The  Company  has  duly  authorized  the  execution  and  delivery  of this
Supplemental Indenture No. 5 to establish the Securities of Series No. 4 and has
duly authorized the issuance of such Securities;  and all acts necessary to make
this Supplemental  Indenture No. 5 a valid agreement of the Company, and to make
the  Securities  of Series No. 4 valid  obligations  of the  Company,  have been
performed.

                               Granting Clauses

     NOW,  THEREFORE,  THIS  SUPPLEMENTAL  INDENTURE NO. 5 WITNESSETH,  that, in
consideration  of the  premises  and of the  purchase of the  Securities  by the
Holders  thereof,  and in order to secure the  payment of the  principal  of and
premium,  if any,  and  interest,  if any, on all  Securities  from time to time
Outstanding  and the performance of the covenants  contained  therein and in the
Indenture and to declare the terms and  conditions on which such  Securities are
secured, the Company hereby grants, bargains, sells, releases, conveys, assigns,
transfers, mortgages, pledges, sets over and confirms to the Trustee, and grants
to the Trustee a security interest in, the following:

                             Granting Clause First

            All right, title and interest of the Company,  as of the date of the
      execution  and delivery of this  Supplemental  Indenture  No. 5, in and to
      property  (other than  Excepted  Property),  real,  personal and mixed and
      wherever situated, in any case used or to be used in or in connection with
      the Electric Utility Business  (whether or not such use is the sole use of
      such property),  including without limitation [(a) all lands and interests
      in land  described  or referred  to in  Schedule B hereto];  (b) all other
      lands, easements,  servitudes,  licenses, permits, rights of way and other
      rights and interests in or relating to real property used or to be used in
      or in connection with the






      Electric Utility Business or relating to the occupancy or use of such real
      property,  subject however,  to the exceptions and exclusions set forth in
      clause (a) of Granting  Clause  First of the Original  Indenture;  (c) all
      plants,  generators,   turbines,   engines,  boilers,  fuel  handling  and
      transportation  facilities, air and water pollution control and sewage and
      solid waste disposal facilities and other machinery and facilities for the
      generation  of  electric  energy;  (d)  all  switchyards,  lines,  towers,
      substations,  transformers  and other  machinery  and  facilities  for the
      transmission  of  electric  energy;  (e)  all  lines,   poles,   conduits,
      conductors,  meters, regulators and other machinery and facilities for the
      distribution of electric energy;  (f) all buildings,  offices,  warehouses
      and  other  structures  used or to be used in or in  connection  with  the
      Electric  Utility  Business;  (g) all pipes,  cables,  insulators,  ducts,
      tools,  computers and other data processing  and/or storage  equipment and
      other  equipment,  apparatus  and  facilities  used or to be used in or in
      connection  with  the  Electric  Utility  Business;  (h) any or all of the
      foregoing  properties  in the process of  construction;  and (i) all other
      property,  of whatever kind and nature,  ancillary to or otherwise used or
      to be used in  conjunction  with any or all of the foregoing or otherwise,
      directly or indirectly, in furtherance of the Electric Utility Business;

                            Granting Clause Second

            Subject to the applicable  exceptions  permitted by Section  810(c),
      Section  1303 and Section  1305 of the  Original  Indenture,  all property
      (other  than  Excepted  Property)  of the kind  and  nature  described  in
      Granting Clause First which may be hereafter  acquired by the Company,  it
      being the intention of the Company that all such property  acquired by the
      Company after the date of the execution and delivery of this  Supplemental
      Indenture  No. 5 shall be as fully  embraced  within and  subjected to the
      Lien hereof as if such  property  were owned by the Company as of the date
      of the execution and delivery of this Supplemental Indenture No. 5;

                            Granting Clause Fourth

            All other property of whatever kind and nature subjected or required
      to be  subjected  to the Lien of the  Indenture  by any of the  provisions
      thereof;

                               Excepted Property

            Expressly  excepting  and  excluding,  however,  from  the  Lien and
      operation of the Indenture all Excepted  Property of the Company,  whether
      now owned or hereafter acquired;

      TO HAVE AND TO HOLD all such property,  real, personal and mixed, unto the
Trustee, its successors in trust and their assigns forever;

      SUBJECT,  HOWEVER,  to (a) Liens existing at the date of the execution and
delivery of the Original Indenture  (including,  but not limited to, the Lien of
the PSCO 1939  Mortgage),  (b) as to property  acquired by the Company after the
date of the execution and delivery of the Original Indenture,  Liens existing or
placed  thereon  at the  time of the  acquisition  thereof  (including,  but not
limited to, the Lien of any Class A Mortgage  and  purchase  money  Liens),  (c)
Retained  Interests and (d) any other Permitted Liens, it being understood that,
with respect to any property  which was at the date of execution and delivery of
the Original Indenture or thereafter became or hereafter becomes

                                     2





subject to the Lien of any Class A Mortgage,  the Lien of the Indenture shall at
all  times be  junior,  subject  and  subordinate  to the  Lien of such  Class A
Mortgage;

      IN  TRUST,  NEVERTHELESS,  for the  equal and  proportionate  benefit  and
security of the Holders from time to time of all Outstanding  Securities without
any priority of any such Security over any other such Security;

      PROVIDED,  HOWEVER,  that the right,  title and interest of the Trustee in
and to the  Mortgaged  Property  shall  cease,  terminate  and  become  void  in
accordance with, and subject to the conditions set forth in, Article Nine of the
Original  Indenture,  and if, thereafter,  the principal of and premium, if any,
and  interest,  if any,  on the  Securities  shall have been paid to the Holders
thereof,  or shall have been paid to the Company  pursuant to Section 603 of the
Original Indenture, then and in that case the Indenture shall terminate, and the
Trustee shall execute and deliver to the Company such instruments as the Company
shall require to evidence such  termination;  otherwise the  Indenture,  and the
estate and rights thereby granted, shall be and remain in full force and effect;
and

      THE PARTIES HEREBY FURTHER COVENANT AND AGREE as follows:

                                  ARTICLE ONE

                          Securities of Series No. 4

      There are hereby  established  the Securities of Series No. 4, which shall
have the terms and  characteristics  set forth below (the lettered  subdivisions
set forth below corresponding to the lettered subdivisions of Section 301 of the
Original Indenture):

     (a)  the  title  of  the  Securities  of  such  series  shall  be  "Secured
     Medium-Term  Notes,  Series B",  being a series of First  Collateral  Trust
     Bonds;  provided,  however,  that, at any time after the PSCO 1939 Mortgage
     shall have been satisfied and discharged, the Company shall have the right,
     without any consent or other action by the Holders of such  Securities,  to
     change  such title in such  manner as shall be deemed by the  Company to be
     appropriate to reflect such  satisfaction and discharge,  such change to be
     evidenced in an Officer's Certificate;

     (b) there  shall be no limit  upon the  aggregate  principal  amount of the
     Securities of Series No. 4 which may be  authenticated  and delivered under
     the  Indenture.   The  Securities  of  Series  No.  4  shall  be  initially
     authenticated  and delivered  from time to time in the aggregate  principal
     amount of up to $250,000,000;

     (c)  interest  on the  Securities  of Series  No. 4 shall be payable to the
     Persons  in whose  names such  Securities  are  registered  at the close of
     business on the Regular Record Date for such interest,  except as otherwise
     expressly  provided  in the form of such  Security  attached  as  Exhibit A
     hereto;

     (d) the principal of each Security of Series No. 4 shall be payable on such
     date  as is  specified  in the  Officer's  Certificate  applicable  to such
     Security;

     (e) an Officer's  Certificate with respect to each Security of Series No. 4
     shall  specify  the rate at which such  Security of Series No. 4 shall bear
     interest,  the date from which interest shall accrue,  the Interest Payment
     Dates if other than February 1

                                     3





     and August 1 of each year and the Regular  Record Dates with respect to the
     Interest Payment Dates if other than January 15 and July 15;

     (f) the  Corporate  Trust  Office  of  First  Trust of New  York,  National
     Association,  in New  York,  New York  shall be the  place at which (i) the
     principal of, premium,  if any, and interest,  if any, on the Securities of
     Series  No. 4 shall be  payable,  (ii)  registration  of  transfer  of such
     Securities  may be  effected,  (iii)  exchanges of such  Securities  may be
     effected  and (iv) notices and demands to or upon the Company in respect of
     such  Securities  and the Indenture  may be served;  and First Trust of New
     York,  National  Association,  shall  be the  Security  Registrar  for  the
     Securities;  provided,  however,  that the  Company  reserves  the right to
     change,  by one or more  Officer's  Certificates,  any  such  place  or the
     Security Registrar;  and provided,  further,  that the Company reserves the
     right to designate,  by one or more Officer's  Certificates,  its principal
     office in  Denver,  Colorado  as any such  place or itself as the  Security
     Registrar;

     (g) each  Security of Series No. 4 shall be  redeemable  only if and to the
     extent specified in the Officer's  Certificate  applicable to such Security
     of Series No. 4;

     (h) not  applicable  to any  Security of Series No. 4, except to the extent
     specified in the Officer's Certificate  applicable to a particular Security
     of Series No. 4;

     (i) the  Securities of Series No. 4 shall be issuable in  denominations  of
     $100,000 and any greater amount which is an integral multiple of $1,000;

     (j) not applicable;

     (k) not applicable;

     (l) not applicable;

     (m) not applicable;

     (n) not  applicable  to any  Security of Series No. 4, except to the extent
     specified in the Officer's Certificate  applicable to a particular Security
     of Series No. 4;

     (o) not applicable;

     (p) not applicable;

     (q) each Security of Series No. 4 is to be initially registered in the name
     of  Cede  &  Co.,  as  nominee  for  The  Depository   Trust  Company  (the
     "Depositary").  The Securities of Series No. 4 shall not be transferable or
     exchangeable,  nor shall any purported  transfer be  registered,  except as
     follows:

          (i) a  Security  of Series  No. 4 may be  transferred  in  whole,  and
          appropriate  registration of transfer effected, if such transfer is by
          such  nominee  to the  Depositary,  or by the  Depositary  to  another
          nominee  thereof,  or by any  nominee of the  Depositary  to any other
          nominee  thereof,  or by the Depositary or any nominee  thereof to any
          successor securities depositary or any nominee thereof; and

                                     4






          (ii) a Security  of Series  No. 4 may be  exchanged  for  certificated
          notes  registered in the respective  names of the  beneficial  holders
          thereof, and thereafter shall be transferable without restriction, if:

                  (A) The Depositary,  or any successor  securities  depositary,
                  shall have  notified  the Company  and the Trustee  that it is
                  unwilling   or  unable  to  continue  to  act  as   securities
                  depositary  with  respect to such  Security of Series No. 4 or
                  the Company becomes aware that the Depositary has ceased to be
                  a clearing agency registered under the Securities Exchange Act
                  of 1934, as amended,  and, in any such case, the Trustee shall
                  not have been notified by the Company  within ninety (90) days
                  of the  identity of a  successor  securities  depositary  with
                  respect to such Security of Series No. 4;

                  (B) The Company shall have  delivered to the Trustee a Company
                  Order to the effect  that such  Security of Series No. 4 shall
                  be so exchangeable on and after a date specified therein; or

                  (C)  (1) an  Event  of  Default  shall  have  occurred  and be
                  continuing,  (2) the Trustee  shall have given  notice of such
                  Event of  Default  pursuant  to Section  1102 of the  Original
                  Indenture  and (3)  there  shall  have been  delivered  to the
                  Company  and the  Trustee  an Opinion of Counsel to the effect
                  that the interests of the  beneficial  owners of such Security
                  of Series No. 4 in respect thereof will be materially impaired
                  unless such owners become Holders of certificated notes.

     (r) not applicable;

     (s) no service  charge  shall be made for the  registration  of transfer or
     exchange  of any  Securities  of Series No. 4 provided,  however,  that the
     Company may require  payment of a sum  sufficient to cover any tax or other
     governmental  charge  payable  in  connection  with  any such  exchange  or
     transfer;

     (t) not applicable;

     (u) (i) If the Company  shall have  caused the  Company's  indebtedness  in
     respect  of any  Security  of  Series  No.  4 to have  been  satisfied  and
     discharged  prior to the  Maturity  of such  Security  of Series  No. 4, as
     provided  in Section 901 of the  Original  Indenture,  the  Company  shall,
     promptly after the date of such  satisfaction and discharge,  give a notice
     to each  Person  who was a Holder of any such  Security  of Series No. 4 on
     such date stating (A)(1) the aggregate principal amount of such Security of
     Series No. 4 and (2) the aggregate amount of any money (other than amounts,
     if any, deposited in respect of accrued interest on such Security of Series
     No. 4) and the aggregate principal amount of, the rate or rates of interest
     on,  and the  aggregate  fair  market  value of, any  Eligible  Obligations
     deposited pursuant to Section 901 of the Original Indenture with respect to
     such  Security of Series No. 4 and (B) that the Company  will  provide (and
     the Company shall  promptly so provide) to such Person,  or any  beneficial
     owner of such  Security of Series No. 4 holding  through  such Person (upon
     written  request  to the  Company  sent  to an  address  specified  in such
     notice),  such other information as such Person or beneficial owner, as the
     case may be,  reasonably may request in order to enable it to determine the
     federal income tax

                                     5





     consequences  to it resulting  from the  satisfaction  and discharge of the
     Company's  indebtedness  in  respect  of such  Security  of  Series  No. 4.
     Thereafter, the Company shall, within forty-five (45) days after the end of
     each  calendar  year,  give to each  Person  who at any  time  during  such
     calendar  year was a  Holder  of such  Security  of  Series  No. 4 a notice
     containing  (X) such  information as may be necessary to enable such Person
     to report its income,  gain or loss for federal  income tax  purposes  with
     respect to such  Security  of Series No. 4 or the assets held on deposit in
     respect  thereof  during such calendar year or the portion  thereof  during
     which  such  Person was a Holder of such  Security  of Series No. 4, as the
     case may be (such  information  to be set forth for such calendar year as a
     whole and for each  month  during  such  year) and (Y) a  statement  to the
     effect that the Company  will provide  (and the Company  shall  promptly so
     provide) to such Person, or any beneficial owner of such Security of Series
     No. 4 holding through such Person (upon written request to the Company sent
     to an address  specified in such notice),  such other  information  as such
     Person or beneficial  owner, as the case may be,  reasonably may request in
     order to enable it to determine its income, gain or loss for federal income
     tax purposes  with respect to such  Security of Series No. 4 or such assets
     for such year or portion thereof, as the case may be. The obligation of the
     Company to provide or cause to be  provided  information  for  purposes  of
     income tax  reporting by any Person as described in the first two sentences
     of this paragraph shall be deemed to have been satisfied to the extent that
     the Company has provided or caused to be provided substantially  comparable
     information  pursuant to any  requirements of the Internal  Revenue Code of
     1986, as amended from time to time (the "Code"), and United States Treasury
     regulations thereunder.

               (ii)  Notwithstanding  the provisions of subparagraph  (i) above,
               the Company shall not be required to give any notice specified in
               such  subparagraph or to otherwise furnish any of the information
               contemplated  therein if the Company shall have  delivered to the
               Trustee an  Opinion  of Counsel to the effect  that the Holder of
               such Security of Series No. 4 will not recognize income,  gain or
               loss  for  federal  income  tax  purposes  as  a  result  of  the
               satisfaction  and  discharge  of the  Company's  indebtedness  in
               respect of such  Security of Series No. 4 and such Holder will be
               subject to federal income taxation on the same amounts and in the
               same  manner  and at the same times as if such  satisfaction  and
               discharge had not occurred.

               (iii)   Anything   in   this   clause   (u)   to   the   contrary
               notwithstanding,  the  Company  shall not be required to give any
               notice specified in subparagraph (i) or to otherwise  furnish the
               information  contemplated  therein or to deliver  any  Opinion of
               Counsel  contemplated by  subparagraph  (ii) if the Company shall
               have caused the applicable  Security of Series No. 4 to be deemed
               to have been paid for purposes of the  Indenture,  as provided in
               Section  901  of the  Original  Indenture,  but  shall  not  have
               effected the  satisfaction  and discharge of its  indebtedness in
               respect  of such  Security  of  Series  No.  4  pursuant  to such
               Section.

               (v) each Security of Series No. 4 shall be  substantially  in the
               form  attached  as Exhibit A hereto  and shall have such  further
               terms as are set forth in such form.


                                     6





                                  ARTICLE TWO

                           Miscellaneous Provisions

     This  Supplemental  Indenture  No.  5  is  a  supplement  to  the  Original
Indenture.   As  previously   supplemented  and  further  supplemented  by  this
Supplemental  Indenture  No.  5,  the  Original  Indenture  is in  all  respects
ratified,  approved  and  confirmed,  and the Original  Indenture,  all previous
supplements  thereto  and  this  Supplemental  Indenture  No.  5 shall  together
constitute one and the same instrument.



                                     7





            IN WITNESS WHEREOF, the parties hereto have caused this Supplemental
Indenture No. 5 to be duly executed as of the day and year first above written.

                                          PUBLIC SERVICE COMPANY OF COLORADO


                                          By:_____________________________
                                               [Name]
                                               Senior Vice President



                                          FIRST TRUST OF NEW YORK,
                                            NATIONAL ASSOCIATION, Trustee


                                          By:_____________________________
                                               [Name]
                                               Vice President




                                     8





STATE OF COLORADO                   )
                                    ) ss.:
CITY AND COUNTY OF DENVER           )


            On the day of , 1996,  before me personally came , to me known, who,
being  by me duly  sworn,  did  depose  and say that he is a of  Public  Service
Company of Colorado, one of the corporations described in and which executed the
foregoing  instrument;  and that he signed his name  thereto by authority of the
Board of Directors of said corporation.



                                            ______________________________
                                            Notary Public



                                     9







STATE OF NEW YORK                         )
                                          ) ss.:
CITY AND COUNTY OF NEW YORK               )


            On  the  day  of   _______,   1996,   before  me   personally   came
______________,  to me known,  who,  being by me duly sworn,  did depose and say
that she is a _______________ of First Trust of New York, National  Association,
the national banking  association  described in and which executed the foregoing
instrument;  and that she signed her name  thereto by  authority of the Board of
Directors of said national banking association.



                                              ____________________________
                                              Notary Public





                                     10





                                                                     EXHIBIT A
                               FORM OF SECURITY


                  (See legend at the end of this Security for
                 restrictions on transfer and change of form)


                      PUBLIC SERVICE COMPANY OF COLORADO


                      Secured Medium-Term Note, Series B
                     (being a First Collateral Trust Bond)


Original Issue Date:             Regular Record Dates:
Interest Rate:                   Initial Redemption Date:
Default Rate:                    Initial Redemption Percentage:
Stated Maturity:                 Annual Redemption Percentage Reduction:
Interest Payment Dates:          Optional Repayment Dates:
Addendum Attached
[  ] Yes                         Other/Additional Provisions:
[  ] No








           This Note is not a Discount Security within the meaning of
                         the within-mentioned Indenture.

                    -----------------------------------------


Principal Amount                                                  Registered No.
$                                                                 CUSIP


      PUBLIC  SERVICE  COMPANY OF COLORADO,  a  corporation  duly  organized and
existing  under the laws of the State of Colorado  (herein called the "Company,"
which term includes any successor  corporation  under the Indenture  referred to
below), for value received, hereby promises to pay to

                                   , or registered assigns, the principal sum of

Dollars  on the  Stated  Maturity  specified  above (or any  Redemption  Date or
Repayment Date as defined below),  and to pay interest thereon from the Original
Issue Date  specified  above or from the most recent  Interest  Payment  Date to
which interest has been paid or duly provided for,  semi-annually  in arrears on
the Interest  Payment Dates  specified  above in each year,  commencing with the
Interest  Payment Date next  succeeding  the Original  Interest  Date  specified
above, and at Maturity, at the Interest Rate per annum

                                    A-1





specified  above,  computed on the basis of a 360-day year  consisting of twelve
30-day months,  until the principal  hereof is paid or duly provided for and, to
the extent that payment of such interest  shall be legally  enforceable,  at the
Default  Rate per annum  specified  above on any overdue  payment of  principal,
premium,  if any,  and/or  interest.  The interest so payable,  and paid or duly
provided for, on any Interest Payment Date shall, as provided in such Indenture,
be paid to the  Person  in whose  name  this  Note  (or one or more  Predecessor
Securities)  is registered  at the close of business on the Regular  Record Date
specified  above  (whether or not a Business Day) next  preceding  such Interest
Payment  Date except that if the  Original  Issue Date of this Note is after the
Regular  Record  Date  specified  above and  before the  corresponding  Interest
Payment  Date,  the first  payment of interest on this Note shall be made to the
Person  in whose  name  this  Note (or one or more  Predecessor  Securities)  is
registered  at the close of business on the Regular  Record Date with respect to
the next  succeeding  Interest  Payment  Date.  Notwithstanding  the  foregoing,
interest payable at Maturity shall be paid to the Person to whom principal shall
be paid. Except as otherwise  provided in said Indenture,  any such interest not
so paid or duly provided for shall  forthwith  cease to be payable to the Holder
on such  Regular  Record Date and may either be paid to the Person in whose name
this Note (or one or more Predecessor  Securities) is registered at the close of
business on a Special Record Date for the payment of such Defaulted  Interest to
be fixed by the Trustee, notice of which shall be given to Holders of Securities
of this series not less than 15 days prior to such Special  Record Date, or paid
in such other manner as permitted by the Indenture.


      Notwithstanding  the  foregoing,  if an  Addendum  is  attached  hereto or
"Other/Additional  Provisions"  apply  to this  Note as  specified  on the  face
hereof,  this Note shall be subject to the terms set forth in such  Addendum  or
such "Other/Additional Provisions".

      Payment of the principal of and premium, if any, on this Note and interest
hereon  at  Maturity  shall be made  upon  presentation  of this  Note (and with
respect to any applicable repayment of this Note, a duly completed election form
as contemplated below) at the Corporate Trust Office of First Trust of New York,
National Association, in New York, New York or at such other office or agency as
may be designated for such purpose by the Company from time to time.  Payment of
interest on this Note (other than  interest at Maturity)  shall be made by check
mailed to the  address of the Person  entitled  thereto  as such  address  shall
appear in the Note  Register,  except that if such Person  shall be a securities
depositary,  such  payment  may be made by such other  means in lieu of check as
shall be agreed upon by the Company, the Trustee and such Person. Payment of the
principal of and premium, if any, and interest on this Note, as aforesaid, shall
be made in such coin or currency of the United  States of America as at the time
of payment shall be legal tender for the payment of public and private debts.

      This Note is one of a duly  authorized  issue of securities of the Company
(herein called the "Notes"), issued and issuable in one or more series under and
equally secured by an Indenture,  dated as of October 1, 1993 (such Indenture as
originally  executed and delivered and as  supplemented  or amended from time to
time  thereafter,  together with any constituent  instruments  establishing  the
terms of particular  Securities,  being herein called the "Indenture"),  between
the Company  and First Trust of New York,  National  Association,  as  successor
trustee (herein called the "Trustee," which term includes any further  successor
trustee under the Indenture), to which Indenture and all indentures supplemental
thereto  reference is hereby made for a description  of the property  mortgaged,
pledged  and held in  trust,  the  nature  and  extent of the  security  and the
respective rights,  limitations of rights, duties and immunities of the Company,
the Trustee and the Holders of the  Securities  thereunder  and of the terms and
conditions  upon which the  Securities  are,  and are to be,  authenticated  and
delivered and secured. The acceptance of this Note shall be deemed to constitute
the  consent  and  agreement  by the  Holder  hereof  to all  of the  terms  and
provisions of the Indenture. This Note is one of the series designated above.


                                    A-2





      If any Interest  Payment Date, any Redemption  Date or the Stated Maturity
shall not be a Business Day (as hereinafter defined), payment of the amounts due
on this Note on such date may be made on the next succeeding  Business Day; and,
if such payment is made or duly  provided for on such  Business Day, no interest
shall accrue on such amounts for the period from and after such Interest Payment
Date,  Redemption Date or Stated Maturity,  as the case may be, to such Business
Day.

      Unless otherwise specified in an Addendum attached hereto, this Note shall
not be subject to any sinking fund or other  mandatory  redemption  and,  unless
otherwise  specified on the face hereof in accordance with the provisions of the
following four  paragraphs,  this Note is not subject to optional  redemption or
repayment prior to the Stated Maturity hereof.

      This Note is subject  to  redemption  at the option of the  Company at any
time on or after the Initial  Redemption  Date,  if any,  specified  on the face
hereof,  as a whole at any time or from time to time in part,  in  increments of
$1,000  (provided that any remaining  principal  amount hereof shall be at least
$100,000),  at the  Redemption  Price (as defined  below),  plus unpaid  accrued
interest  hereon to the date fixed for redemption  (each, a "Redemption  Date").
The  "Redemption  Price" shall  initially be the Initial  Redemption  Percentage
specified on the face hereof  multiplied by the unpaid  principal amount of this
Note to be redeemed.  The Initial  Redemption  Percentage  shall decline at each
anniversary of the Initial Redemption Date by the Annual Redemption  Percentage,
if any,  specified on the face hereof until the Redemption  Price is 100% of the
unpaid principal amount to be redeemed.

      Notice of  redemption  shall be given by mail to the  Holder of this Note,
not less  than 30 days  nor  more  than 60 days  prior  to the  date  fixed  for
redemption,  all as provided  in the  Indenture.  As provided in the  Indenture,
notice of  redemption at the election of the Company as aforesaid may state that
such  redemption  shall be  conditional  upon the receipt by the Paying Agent or
Agents for this  Note,  on or prior to the date  fixed for such  redemption,  of
money sufficient to pay the principal of and premium,  if any, and interest,  on
this Note; a notice of redemption so conditioned  shall be of no force or effect
if such money is not so received  and, in such event,  the Company  shall not be
required to redeem this Note.

      In the event of  redemption of this Note in part only, a new Note or Notes
of this series,  of like tenor, for the unredeemed  portion hereof and otherwise
having  the same  terms as this Note  will be  issued in the name of the  Holder
hereof upon the cancellation hereof.

      This Note will be subject to repayment by the Company at the option of the
Holder hereof on the Optional Repayment  Date(s),  if any, specified on the face
hereof, in whole or in part in increments of $1,000 (provided that any remaining
principal amount hereof shall be at least $100,000),  at a repayment price equal
to 100% of the  unpaid  principal  amount to be  repaid,  plus  unpaid  interest
accrued hereon to the date fixed for repayment  (each a "Repayment  Date").  For
this Note to be  repaid,  this Note must be  received  not more than 60 nor less
than 30 calendar days prior to the Repayment Date, together with the form hereon
entitled  "Option to Elect  Repayment"  duly  completed,  by the  Trustee at its
Corporate  Trust Office in New York,  New York or such other office or agency as
may be designated by the Company from time to time.  Exercise of such  repayment
option by the Holder  hereof will be  irrevocable.  In the event of repayment of
this  Note in part  only,  a new Note or Notes of like  tenor  for the  unrepaid
portion  hereof and otherwise  having the same terms as this Note will be issued
in the name of the Holder hereof upon the cancellation hereof.

      If an Event of Default  shall occur and be  continuing,  the  principal of
this Note may be  declared  due and  payable  in the  manner and with the effect
provided in the Indenture.


                                    A-3





      The Indenture permits,  with certain  exceptions as therein provided,  the
Trustee to enter into one or more  supplemental  indentures  for the  purpose of
adding any provisions  to, or changing in any manner or  eliminating  any of the
provisions  of, the Indenture with the consent of the Holders of not less than a
majority in  aggregate  principal  amount of the  Securities  of all series then
Outstanding  under the Indenture,  considered as one class;  provided,  however,
that if there shall be Securities of more than one series  Outstanding under the
Indenture and if a proposed  supplemental  indenture  shall directly  affect the
rights of the Holders of Securities  of one or more,  but less than all, of such
series,  then  the  consent  only of the  Holders  of a  majority  in  aggregate
principal  amount  of the  Outstanding  Securities  of all  series  so  directly
affected,  considered as one class,  shall be required;  and provided,  further,
that if the  Securities  of any series  shall have been  issued in more than one
Tranche and if the proposed  supplemental  indenture  shall directly  affect the
rights of the Holders of Securities  of one or more,  but less than all, of such
Tranches,  then the  consent  only of the  Holders  of a majority  in  aggregate
principal  amount of the  Outstanding  Securities  of all  Tranches  so directly
affected,  considered as one class,  shall be required;  and provided,  further,
that the  Indenture  permits the Trustee to enter into one or more  supplemental
indentures  for  limited   purposes  without  the  consent  of  any  Holders  of
Securities.  The Indenture also contains provisions  permitting the Holders of a
majority in principal  amount of the Securities then  Outstanding,  on behalf of
the Holders of all Securities,  to waive  compliance by the Company with certain
provisions of the  Indenture  and certain past defaults  under the Indenture and
their consequences.  Any such consent or waiver by the Holder of this Note shall
be conclusive  and binding upon such Holder and upon all future  Holders of this
Note and of any Note  issued  upon the  registration  of  transfer  hereof or in
exchange therefor or in lieu hereof,  whether or not notation of such consent or
waiver is made upon this Note.

      As provided in the  Indenture and subject to certain  limitations  therein
set forth,  this Note or any  portion of the  principal  amount  hereof  will be
deemed to have been paid for all purposes of the  Indenture  and to be no longer
Outstanding  thereunder,  and, at the  election of the  Company,  the  Company's
entire  indebtedness  in respect  thereof will be satisfied and  discharged,  if
there has been irrevocably deposited with the Trustee or any Paying Agent (other
than the Company),  in trust, money in an amount which will be sufficient and/or
Eligible  Obligations,  the principal of and interest on which when due, without
regard to any  reinvestment  thereof,  will provide moneys which,  together with
moneys so deposited,  will be  sufficient,  to pay when due the principal of and
premium, if any, and interest on this Note when due.

      As provided in the  Indenture and subject to certain  limitations  therein
set forth,  the transfer of this Note is registrable  in the Security  Register,
upon surrender of this Note for  registration of transfer at the Corporate Trust
Office of First Trust of New York, National  Association,  in New York, New York
or such other office or agency as may be  designated by the Company from time to
time,  duly endorsed by, or accompanied  by a written  instrument of transfer in
form  satisfactory  to the Company and the Security  Registrar duly executed by,
the Holder hereof or his attorney duly authorized in writing,  and thereupon one
or more new  Securities of this series of authorized  denominations  and of like
tenor  and  aggregate  principal  amount,  will  be  issued  to  the  designated
transferee or transferees.

      The Notes are issuable only as registered Notes,  without coupons,  and in
denominations  of $100,000  and in any greater  amount in integral  multiples of
$1,000. As provided in the Indenture and subject to certain  limitations therein
set forth, the Notes are  exchangeable for a like aggregate  principal amount of
Notes of the same  series  and  Tranche,  of any  authorized  denominations,  as
requested by the Holder  surrendering the same, and of like tenor upon surrender
of the Note or Notes to be  exchanged  at the  Corporate  Trust  Office of First
Trust of New York,  National  Association,  in New York,  New York or such other
office or agency as may be designated by the Company from time to time.


                                    A-4





      The  Company  shall  not  be  required  to  execute  or  provide  for  the
registration  of transfer of or the  exchange of this Note during a period of 15
days  immediately  preceding  the date notice is given  calling this Note or any
part hereof for redemption, except with respect to the unredeemed portion of any
Note being redeemed in part.

      No service charge shall be made for any such  registration  of transfer or
exchange,  but the Company may require  payment of a sum sufficient to cover any
tax or other governmental charge payable in connection therewith.

      Prior to due presentment of this Note for  registration  of transfer,  the
Company,  the  Trustee and any agent of the Company or the Trustee may treat the
Person in whose name this Note is  registered  as the absolute  owner hereof for
all purposes,  whether or not this Note be overdue, and neither the Company, the
Trustee nor any such agent shall be affected by notice to the contrary.

      The  Indenture  and  this  Note  shall be  governed  by and  construed  in
accordance with the laws of the State of New York.

      As used  herein  "Business  Day" means any day,  other than a Saturday  or
Sunday,  which is not a day on which banking  institutions or trust companies in
The City of New York,  New York or other city in which is located  any office or
agency  maintained  for the payment of the principal of, or premium,  if any, or
interest on this Note, are generally  authorized or required by law,  regulation
or executive order to remain closed. All other terms used in this Note which are
defined  in the  Indenture  shall  have  the  meanings  assigned  to them in the
Indenture.

      As provided in the Indenture,  no recourse shall be had for the payment of
the principal of, premium,  if any, or interest on any  Securities,  or any part
thereof,  or for any claim based thereon or otherwise in respect thereof,  or of
the  indebtedness  represented  thereby,  or upon any  obligation,  covenant  or
agreement under the Indenture,  against,  and no personal  liability  whatsoever
shall attach to, or be incurred by, any  incorporator,  shareholder,  officer or
director,  as such, past, present or future of the Company or of any predecessor
or  successor   corporation  (either  directly  or  through  the  Company  or  a
predecessor or successor  corporation),  whether by virtue of any constitutional
provision,  statute or rule of law, or by the  enforcement  of any assessment or
penalty  or  otherwise;  it  being  expressly  agreed  and  understood  that the
Indenture and all the Securities are solely  corporate  obligations and that any
such personal  liability is hereby  expressly waived and released as a condition
of, and as part of the consideration for, the execution of the Indenture and the
issuance of the Securities.

      Unless the certificate of  authentication  hereon has been executed by the
Trustee or an Authenticating  Agent by manual signature,  this Note shall not be
entitled to any benefit under the  Indenture or be valid or  obligatory  for any
purpose.


                                    A-5





      IN WITNESS  WHEREOF,  the Company has caused  this  instrument  to be duly
executed under its corporate seal to be hereunto affixed and attested.

                                    PUBLIC SERVICE COMPANY OF COLORADO



                                    By:___________________________________
                                          Senior Vice President


Attest:

______________________________
      Secretary


                         CERTIFICATE OF AUTHENTICATION

      This is one of the Securities of the series designated therein referred to
in the within-mentioned Indenture.

Dated:_______________

FIRST TRUST OF NEW YORK,      OR          FIRST TRUST OF NEW YORK,
NATIONAL ASSOCIATION                      NATIONAL ASSOCIATION,
  as Trustee                                 as Trustee



By:__________________________             By:  [                     ],
         Authorized Officer                    as Authenticating Agent


                                          By:_____________________________
                                               Authorized Officer

      Unless this  certificate is presented by an authorized  representative  of
The Depository Trust Company, a New York corporation  ("DTC"), to the Company or
its  agent  for  registration  of  transfer,   exchange,  or  payment,  and  any
certificate issued is registered in the name of Cede & Co. or in such other name
as is requested by an authorized  representative of DTC (and any payment is made
to  Cede  & Co.  or to  such  other  entity  as is  requested  by an  authorized
representative  of DTC), ANY TRANSFER,  PLEDGE, OR OTHER USE HEREOF FOR VALUE OR
OTHERWISE  BY OR TO ANY PERSON IS  WRONGFUL  inasmuch  as the  registered  owner
hereof, Cede & Co., has an interest herein.

      This  Note may not be  transferred  or  exchanged,  nor may any  purported
transfer be registered,  except (i) this Note may be  transferred in whole,  and
appropriate  registration  of transfer  effected,  if such transfer is by Cede &
Co., as nominee for The  Depository  Trust  Company (the  "Depositary"),  to the
Depositary,  or by the Depositary to another nominee thereof,  or by any nominee
of the  Depositary to any other  nominee  thereof,  or by the  Depositary or any
nominee thereof to any successor  securities  depositary or any nominee thereof;
and (ii) this Note may be  exchanged  for  definitive  Notes  registered  in the
respective  names of the beneficial  holders  hereof,  and  thereafter  shall be
transferable  without  restrictions  if: (A) the  Depositary,  or any  successor
securities  depositary,  shall have notified the Company and the Trustee that it
is unwilling or unable to continue to act as securities  depositary with respect
to this Note or the Company becomes aware that the Depositary has ceased to be a
clearing agency registered under the Securities Exchange Act of 1934,

                                    A-6





as amended, and in any such case the Trustee shall not have been notified by the
Company  within  ninety  (90) days of the  identity  of a  successor  securities
depositary  with respect to this Note;  (B) the Company shall have  delivered to
the Trustee an  Officer's  Certificate  to the effect that this Note shall be so
exchangeable  on and  after a date  specified  therein;  or  (C)(1)  an Event of
Default shall have occurred and be continuing,  (2) the Trustee shall have given
notice of such Event of Default  pursuant to Section 1102 of the  Indenture  and
(3) there shall have been delivered to the Company and the Trustee an Opinion of
Counsel to the effect that the interests of the  beneficial  owners of this Note
in respect thereof will be materially impaired unless such owners become Holders
of definitive Notes.

                             ________________

   FOR VALUE RECEIVED the undersigned hereby sells, assigns and transfers unto

- --------------------------------------------------------------------------------

     [please insert social security or other identifying number of assignee]

- --------------------------------------------------------------------------------

            [please print or typewrite name and address of assignee]

- --------------------------------------------------------------------------------

the  within  Note  of  PUBLIC  SERVICE  COMPANY  OF  COLORADO  and  does  hereby
irrevocably constitute and appoint ________________,  Attorney, to transfer said
Note  on  the  books  of  the   within-mentioned   Company,with  full  power  of
substitution in the premises.



Dated:__________________



           __________________________________________________________
      Notice:  The signature to this assignment must correspond with the name as
      written upon the face of the Note in every particular  without  alteration
      or enlargement or any change whatsoever.


                                    A-7





                           OPTION TO ELECT REPAYMENT

The  undersigned  hereby  irrevocably  request(s) and instruct(s) the Company to
repay this Note (or portion hereof  specified  below) pursuant to its terms at a
price equal to 100% of the principal  amount to be repaid,  together with unpaid
interest  accrued  hereon  to  the  Repayment  Date,  to  the  undersigned,   at
_______________________________________________________________________________
         (Please print or typewrite name and address of the undersigned)

      For this Note to be repaid,  the  Trustee  must  receive at its  Corporate
Trust  Office in New York,  New York not more than 60 nor less than 30  calendar
days  prior  to the  Repayment  Date,  this  Note  with  this  "Option  to Elect
Repayment" form duly completed.

      If less than the  entire  principal  amount of this Note is to be  repaid,
specify the portion  hereof (which shall be increments of $1,000  (provided that
any remaining  principal  amount hereof shall be at least  $100,000))  which the
Holder  elects to have  repaid and  specify the  denomination  or  denominations
(which  shall be a minimum of  $100,000) of the Notes to be issued to the Holder
for the  portion  of this  Note not being  repaid  (in the  absence  of any such
specification, one such Note will be issued for the portion not being repaid).


Principal Amount
to be Repaid:  $____________                  _________________________________

Date:_______________________                  Notice:  The  signature(s) on this
                                              Option   to  Elect Repayment  must
                                              correspond   with  the  name(s) as
                                              written upon the face of this Note
                                              in   every   particular,   without
                                              alteration  or  enlargement or any
                                              change whatsoever.



                                    A-8







                                                                    SCHEDULE A

                            SUPPLEMENTAL INDENTURES


     Date of                                                          Principal
  Supplemental                                      Principal           Amount
    Indenture            Series of Bonds          Amount Issued      Outstanding
    ---------            ---------------          -------------      -----------
   
November 1, 1993           Series No. 1           $134,500,000      $134,500,000

January 1, 1994     Series No. 2 due 2001 and     $102,667,000      $102,667,000
                      Series No. 2 due 2024       $110,000,000      $110,000,000

September 2, 1994         Appointment of              None              None
                        Successor Trustee

May 1, 1996           Series No. 3 due 2006       $125,000,000      $125,000,000




                                    I-1




                                                                    SCHEDULE B

                            DESCRIPTION OF PROPERTY







                                    II-1