EXHIBIT 4(A)


Nevada Power Company
6226 W. Sahara Avenue
P.O. Box 230
Las Vegas, Nevada  89146

================================================================================

                              NEVADA POWER COMPANY

                                       TO

                              THE BANK OF NEW YORK
                                     Trustee

                                   ----------

                          SECOND SUPPLEMENTAL INDENTURE

                           Dated as of October 1, 2001

                                   ----------

     Supplementing and Amending the General and Refunding Mortgage Indenture
                             Dated as of May 1, 2001

         THIS INSTRUMENT GRANTS A SECURITY INTEREST BY A PUBLIC UTILITY

           THIS INSTRUMENT CONTAINS AFTER-ACQUIRED PROPERTY PROVISIONS

This instrument is being filed pursuant to Nevada Revised Statutes Chapter 105

================================================================================



         SECOND SUPPLEMENTAL INDENTURE, dated as of October 1, 2001, between
NEVADA POWER COMPANY, a corporation duly organized and existing under the laws
of the State of Nevada (herein called the "Company"), having its principal
office at 6226 W. Sahara Avenue, P.O. Box 230, Las Vegas, Nevada 89146, and THE
BANK OF NEW YORK, a New York banking corporation duly organized and existing
under the laws of the State of New York, as Trustee (herein called the
"Trustee"), the office of the Trustee at which on the date hereof its corporate
trust business is principally administered being 101 Barclay Street, New York,
New York 10286.

                             RECITALS OF THE COMPANY

         WHEREAS, the Company has heretofore executed and delivered to the
Trustee a General and Refunding Mortgage Indenture dated as of May 1, 2001 (as
heretofore supplemented, the "Indenture"), providing for the issuance by the
Company from time to time of its bonds, notes or other evidence of indebtedness
to be issued in one or more series (in the Indenture and herein called the
"Securities") and to provide security for the payment of the principal of and
premium, if any, and interest; if any, on the Securities; and

         WHEREAS, the Company, in the exercise of the power and authority
conferred upon and reserved to it under the provisions of the Indenture and
pursuant to appropriate resolutions of the Board of Directors, has duly
determined to make, execute and deliver to the Trustee this Second Supplemental
Indenture to the Indenture as permitted by Sections 2.01, 3.01 and 14.01 of the
Indenture in order to establish the form or terms of, and to provide for the
creation and issuance of, a second series of Securities under the Indenture in
an initial aggregate principal amount of $140,000,000 (such second series being
hereinafter referred to as the "Second Series") and to correct certain defective
provisions in the Indenture; and

         WHEREAS, all things necessary to make the Securities of the Second
Series, when executed by the Company and authenticated and delivered by the
Trustee or any Authenticating Agent and issued upon the terms and subject to the
conditions hereinafter and in the Indenture set forth against payment therefor
the valid, binding and legal obligations of the Company and to make this Second
Supplemental Indenture a valid, binding and legal agreement of the Company, have
been done;

         NOW, THEREFORE, THIS SECOND SUPPLEMENTAL INDENTURE WITNESSETH that, in
order to establish the terms of a series of Securities, to correct certain
defective provisions in the Indenture and for and in consideration of the
premises and of the covenants contained in the Indenture and in this Second
Supplemental Indenture and for other good and valuable consideration the receipt
and sufficiency of which are hereby acknowledged, it is mutually covenanted and
agreed as follows:

                                       1




                                   ARTICLE ONE

                        DEFINITIONS AND OTHER PROVISIONS
                             OF GENERAL APPLICATION

         Section 1.01 Definitions. Each capitalized term that is used herein and
                      -----------
is defined in the Indenture shall have the meaning specified in the Indenture
unless such term is otherwise defined herein.

                                   ARTICLE TWO

                       TITLE, FORM AND TERMS OF THE NOTES

         Section 2.01 Title of the Notes. This Second Supplemental Indenture
                      ------------------
hereby creates a series of Securities designated as the "General and Refunding
Mortgage Notes, Floating Rate, Series B, due October 15, 2003" of the Company
(collectively referred to herein as the "Notes"). For purposes of the
Indenture, the Notes shall constitute a single series of Securities and may be
issued in an unlimited principal aggregate amount, although the initial
issuance of the Notes shall be in the principal amount of $140,000,000.

         Section 2.02 Form and Terms of the Notes. The form and terms of the
                      ---------------------------
Notes will be set forth in an Officer's Certificate delivered by the Company to
the Trustee pursuant to the authority granted by this Second Supplemental
Indenture in accordance with Sections 2.01 and 3.01 of the Indenture.

         Section 2.03 Treatment of Proceeds of Title Insurance Policy. Any
                      -----------------------------------------------
moneys received by the Trustee as proceeds of any title insurance policy on
Mortgaged Property of the Company shall be subject to and treated in accordance
with the provisions of 6.07(b) of the Indenture (other than the last paragraph
thereof).

                                  ARTICLE THREE

  AMENDMENTS TO THE GENERAL AND REFUNDING MORTGAGE INDENTURE DATED MAY 1, 2001

         The Indenture is hereby amended, as permitted by Section 14.01(j) of
                                                                  -------
the Indenture, as follows:

         Section 3.01 Amendment to General Definitions. The definition of
                      --------------------------------
"Expert's Certificate" in Section 1.01 of the Indenture is hereby amended by
deleting the reference to Section "4.03" and inserting a reference to Section
"4.02" in its place and by deleting the reference to Section "7.07" in its
entirety.

         Section 3.02 Amendment to Funded Property Definition. Section 1.02(a)
                      ---------------------------------------
of the Indenture is hereby amended by deleting it in its entirety and inserting
the following definition in its place:

                                       2



                           "(a)     all Property Additions to the extent that
                  the same shall have been designated in an Initial Expert's
                  Certificate to be deemed to be Funded Property;"

         Section 3.03 Amendment to Issuance of Securities on the Basis of
                      ---------------------------------------------------
Retired Securities. Section 4.03(a) of the Indenture is hereby amended by
- ------------------
deleting the words "Subject to the provisions of subsection (c) of this
Section,".

                                  ARTICLE FOUR

                            MISCELLANEOUS PROVISIONS

         The Trustee makes no undertaking or representations in respect of, and
shall not be responsible in any manner whatsoever for and in respect of, the
validity or sufficiency of this Second Supplemental Indenture or the proper
authorization or the due execution hereof by the Company or for or in respect of
the recitals and statements contained herein, all of which recitals and
statements are made solely by the Company.

         Except as expressly amended and supplemented hereby, the Indenture
shall continue in full force and effect in accordance with the provisions
thereof and the Indenture is in all respects hereby ratified and confirmed. This
Second Supplemental Indenture and all of its provisions shall be deemed a part
of the Indenture in the manner and to the extent herein and therein provided.

         This Second Supplemental Indenture shall be governed by, and construed
in accordance with, the laws of the State of New York (including without
limitation Section 5-1401 of the New York General Obligations Law or any
successor to such statute).

         This Second Supplemental Indenture may be executed in any number of
counterparts, each of which so executed shall be deemed to be an original, but
all such counterparts shall together constitute but one and the same instrument.

                                       3



                  IN WITNESS WHEREOF, the parties hereto have caused this
Indenture to be duly executed as of the day and year first above written.

                                    NEVADA POWER COMPANY

                                    By:__________________________________
                                       Name:
                                       Title:

[Seal]

                                    THE BANK OF NEW YORK, as Trustee

                                    By:__________________________________
                                       Name:
                                       Title:

Nevada Form Acknowledgement
- ---------------------------

STATE OF NEVADA                  )
                                 )
COUNTY OF WASHOE                 )


         This instrument was acknowledged before me on October __, 2001, by
______________________as_______________________of________________________.

(Seal, if any)                     ____________________________________
                                                Notary

                                   (My commission expires:____________)



STATE OF ILLINOIS                )
                                 ) ss.:
COUNTY OF COOK                   )

         On the ___ day of October in the year 2001 before me, the undersigned,
personally appeared ____________________, personally known to me or proved to me
on the basis of satisfactory evidence to be the individual whose name is
subscribed to the within instrument and acknowledged to me that he executed the
same in his capacity, and that by his signature on the instrument, the
individual, or the person upon behalf of which the individual acted, executed
the instrument.

                                       ______________________________________