1
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                   SCHEDULE TO

        TENDER OFFER STATEMENT UNDER SECTION 14(D)(1) OR 13(E)(1) OF THE
                         SECURITIES EXCHANGE ACT OF 1934
                                       AND
                                  SCHEDULE 13D
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                                (AMENDMENT NO. 4)


                  Springhill Lake Investors Limited Partnership
- --------------------------------------------------------------------------------
                        (Name of Subject Company (Issuer))

                        AIMCO Properties, L.P. -- Offeror
- --------------------------------------------------------------------------------
            (Names of Filing Persons (Identifying Status as Offeror,
                            Issuer or Other Person))

                            Limited Partnership Units
- --------------------------------------------------------------------------------
                           (Title of Class Securities)

                                      None
- --------------------------------------------------------------------------------
                       (CUSIP Number of Class Securities)

                                 Patrick J. Foye
                   Apartment Investment And Management Company
                           Colorado Center, Tower Two
                   2000 South Colorado Boulevard, Suite 2-1000
                             Denver, Colorado 80222
                                 (303) 757-8101
- --------------------------------------------------------------------------------
           (Name, address, and telephone numbers of person authorized
       to receive notices and communications on behalf of filing persons)

                                    Copy To:

                              Jonathan L. Friedman
                    Skadden, Arps, Slate, Meagher & Flom LLP
                       300 South Grand Avenue, 34th Floor
                          Los Angeles, California 90071
                                 (213) 687-5000



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- --------------------------------------------------------------------------------
Transaction valuation*                                     Amount of filing fee
- --------------------------------------------------------------------------------
$16,463,855                                                $3,292.77
- --------------------------------------------------------------------------------

*        For purposes of calculating the fee only. This amount assumes the
         purchase of 280.15 units of limited partnership interest of the subject
         partnership for $58,768 per unit. The amount of the filing fee,
         calculated in accordance with Section 14(g)(1)(B)(3) and Rule 0-11(d)
         under the Securities Exchange Act of 1934, as amended, equals 1/50th of
         one percent of the aggregate of the cash offered by the bidder.

[ ]      Check the box if any part of the fee is offset as provided by Rule
         0-11(a)(2) and identify the filing with which the offsetting fee was
         previously paid. Identify the previous filing by registration statement
         number, or the Form or Schedule and the date of its filing.

Amount Previously Paid:  $                      Filing Party:

Form or Registration No.:                       Date Filed:

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

[ ]  Check the box if the filing relates solely to preliminary communications
made before the commencement of a tender offer.

Check the appropriate boxes below to designate any transactions to which the
statement relates:

[X]  third-party tender offer subject to Rule 14d-1

[ ]  issuer tender offer subject to Rule 13e-4

[ ]  going-private transaction subject to Rule 13e-3

[X]  amendment to Schedule 13D under Rule 13d-2

Check the following box if the filing is a final amendment reporting the results
of the tender offer: [ ]



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CUSIP No.   NONE

1.       NAME OF REPORTING PERSONS
         S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (entities only)

                  AIMCO PROPERTIES, L.P.
                  84-1275721

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF GROUP
                                                                  (a)  [ ]
                                                                  (b)  [X]
3.       SEC USE ONLY

4.       SOURCE OF FUNDS

                  WC, BK

5.       (CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
         ITEMS 2(d) OR 2(e))                                           [ ]

6.       CITIZENSHIP OR PLACE OF ORGANIZATION

                  Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON

         7.       SOLE VOTING POWER


         8.       SHARED DISPOSITIVE POWER
                           69.50

         9.       SOLE DISPOSITIVE POWER

         10.      SHARED DISPOSITIVE POWER
                           69.50

11.      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                           69.50

12.      CHECK IF THE AGGREGATE AMOUNT IN ROW (7) EXCLUDES CERTAIN SHARES
                                                                       [ ]

13.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (7)

                  Approximately 10.70%

14.      TYPE OF REPORTING PERSON

                  PN


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CUSIP No.   NONE

1.       NAME OF REPORTING PERSONS
         S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (entities only)

                  AIMCO-GP, INC.

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF GROUP
                                                               (a) [ ]
                                                               (b) [X]
3.       SEC USE ONLY

4.       SOURCE OF FUNDS

                  Not Applicable

5.       (CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
         ITEMS 2(d) OR 2(e))                                       [ ]

6.       CITIZENSHIP OR PLACE OF ORGANIZATION

                  Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON

         7.       SOLE VOTING POWER
                           69.50

         8.       SHARED VOTING POWER

         9.       SOLE DISPOSITIVE POWER
                           69.50

         10.      SHARED DISPOSITIVE POWER

11.      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                           69.50

12.      CHECK IF THE AGGREGATE AMOUNT IN ROW (7) EXCLUDES CERTAIN SHARES
                                                                   [ ]
13.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (7)

                    Approximately 10.7%

14.      TYPE OF REPORTING PERSON

                  CO


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CUSIP No.   NONE

1.       NAME OF REPORTING PERSONS
         S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (entities only)

                  APARTMENT INVESTMENT AND MANAGEMENT COMPANY
                  84-129577

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF GROUP
                                                                  (a)  [ ]
                                                                  (b)  [X]
3.       SEC USE ONLY

4.       SOURCE OF FUNDS

                  Not Applicable

5.       (CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
         ITEMS 2(d) OR 2(e))                                           [ ]

6.       CITIZENSHIP OR PLACE OF ORGANIZATION

                  Maryland

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON

         7.       SOLE VOTING POWER
                           241.15

         8.       SHARED VOTING POWER
                           69.50

         9.       SOLE DISPOSITIVE POWER
                           241.15

         10.      SHARED DISPOSITIVE POWER
                           69.50

11.      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                           310.66

12.      CHECK IF THE AGGREGATE AMOUNT IN ROW (7) EXCLUDES CERTAIN SHARES
                                                                       [ ]

13.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (7)

                     Approximately 47.86%

14.      TYPE OF REPORTING PERSON

                  CO


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            TENDER OFFER STATEMENT/AMENDMENT NO. 4 TO SCHEDULE 13D

            This Statement (the "Statement") constitutes (a) the Tender Offer
Statement on Schedule TO of AIMCO Properties, L.P. (the "AIMCO OP"), relating to
an offer to purchase units of limited partnership interest ("Units") of
Springhill Lake Investors Limited Partnership (the "Partnership"); and (b)
Amendment No. 4 to the Schedule 13D (the "Schedule 13D") originally filed with
the Securities and Exchange Commission (the "Commission") on November 19, 1999,
by Insignia Properties Trust ("IPT"), Insignia Financial Group, Inc.
("Insignia") and Andrew L. Farkas, as amended by (i) Amendment No. 1, filed with
the Commission on May 27, 1999, by AIMCO OP, AIMCO-GP, Inc. ("AIMCO-GP") and
Apartment Investment and Management Company ("AIMCO"), (ii) Amendment No. 2,
filed with the Commission on July 8, 1999, by AIMCO OP, AIMCO-GP, Inc. and
Apartment Investment and Management Company, and (iii) Amendment No. 3, filed
with the Commission on July 30, 1999, by AIMCO OP, AIMCO-GP, Inc. and Apartment
Investment and Management Company.

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

            The information in the "Offer to Purchase" of AIMCO Properties,
L.P., dated May 15, 2000 (the "Offer"), Exhibit (a)(1) hereto, is incorporated
herein by reference in answer to all of the Items of this Schedule TO except as
otherwise set forth below:

Item 3.  Identity and Background of Filing Person.

            (a) This Statement is being filed by AIMCO Properties, L.P., a
Delaware limited partnership, and, insofar as this Statement constitutes
Amendment No. 4 to the Schedule 13D, by AIMCO Properties, L.P., a Delaware
limited partnership, AIMCO-GP, Inc., a Delaware corporation and Apartment
Investments and Management Company, a Maryland corporation ( the "Reporting
Person"). The principal business of the Reporting Person is the ownership,
acquisition, development, expansion and management of multi-family apartment
properties. The principal executive offices and telephone number of the
Reporting Person are located at Colorado Center, Tower Two, 2000 South Colorado
Boulevard, Suite 2-1000, Denver, Colorado 80222; (303) 757-8101.

            During the last five years, none of the Reporting Person nor, to the
best of their knowledge, any of the persons listed in Annex I to the Offer (i)
has been convicted in a criminal proceeding (excluding traffic violations or
similar misdemeanors) or (ii) was a party to a civil proceeding of a judicial or
administrative body of competent jurisdiction and as a result of such proceeding
was or is subject to a judgment, decree or final order enjoining further
violations of or prohibiting activities subject to federal or state securities
laws or finding any violation with respect to such laws.

Item 5.  Past Contacts, Transactions, Negotiations and Agreements.

            Except as described in the Offer, none of the events set forth in
Item 1005(b) of Regulation S-K has occurred.

Item 6.  Purposes of the Transaction and Plans or Proposals.

            Except as set forth in the Offer, none of the events set forth in
Item 1006(c) of Regulations S-K is planned, proposed or being negotiated.




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Item 7.  Source and Amount of Funds or Other Consideration.

            Except as set forth in the Offer, there are no alternative plans to
finance the tender offer and no plans to repay any borrowed funds used in the
tender offer.

Item 8.  Interest in Securities of the Subject Company.

            (a)-(b) AIMCO directly owns 241.15 Units and AIMCO OP directly owns
69.50 Units, representing 37.16% and 40.7% (aggregate of 47.06%) of the
outstanding Units based on the 649 Units outstanding at December 31, 1999.

            AIMCO-GP and AIMCO may be deemed to beneficially own the Units
directly owned by AIMCO OP by each of their relationships with AIMCO OP.
AIMCO-GP is the sole general partner of AIMCO OP (owning approximately 1% of the
total equity interests). AIMCO-GP is a wholly owned subsidiary of AIMCO.

            Accordingly, for purposes of this Statement; (i) AIMCO OP is
reporting that it shares the power to vote or direct the power to vote and the
power to dispose or direct the disposition of the 69.50 Units directly by its;
(ii) AIMCO-GP is reporting that it shares the power to vote or direct the
disposition of the 69.50 Units owned by AIMCO OP; and (iii) AIMCO is reporting
that it shares the power to vote or direct the vote and the power to dispose or
direct the disposition of the 69.50 Units directly owned by AIMCO-GP, and it has
the sole power to vote or direct the power to vote and the sole power to dispose
or direct the disposition of the 241.15 Units directly owned by it.

Item 10.  Financial Statements.

            The financial statements included in AIMCO OP's Annual Report on
Form 10-K for the year ended December 31, 1999, which are listed on the Index to
Financial Statements on page F-1 of such Report, are incorporated herein by
reference. Such report may be inspected at the public reference facilities
maintained by the Commission at Judiciary Plaza, 450 Fifth Street, N.W.,
Washington, D.C. 20549; Citicorp Center, 500 West Madison Street, Chicago,
Illinois 60661; and 7 World Trade Center, 13th Floor, New York, New York 10048.
Copies of such material can also be obtained from the Public Reference Room of
the Commission in Washington, D.C. at prescribed rates and from the Commission's
web site at www.sec.gov.

Item 12.  Exhibits.

         (a)(1)      Offer to Purchase, dated May 15, 2000

         (a)(2)(i)   Letter of Transmittal and related Instructions (Annex II to
                     Exhibit (a)(1).)

         (a)(2)(ii)  Acknowledgment and Agreement

         (a)(3)      Letter, dated May 15, 2000, from AIMCO OP to the limited
                     partners of the Partnership

         (b)(1)      Credit Agreement (Secured Revolving Credit Facility), dated
                     as of August 16, 1999, among AIMCO Properties, L.P., Bank
                     of America, Bank Boston, N.A., and First Union National
                     Bank. (Exhibit 10.1 to AIMCO's Current Report on Form 8-K,
                     dated August 16, 1999, is incorporated herein by this
                     reference.)

         (b)(2)      Amended and Restated Credit Agreement, dated as of March
                     15, 2000, among AIMCO Properties, L.P., Bank of America,
                     Bank Boston, N.A., and First Union National Bank. (Exhibit
                     10.20 to AIMCO Properties, L.P.'s Annual Report on Form
                     10-K for the year ended December 31, 1999, is incorporated
                     herein by this reference.)

         (b)(3)      First Amendment to $345,000,000 Amended and Restated Credit
                     Agreement, dated as of April 14, 2000, among AIMCO
                     Properties, L.P., Bank of America, as Administrative Agent,
                     and U.S. Bank National Association, as Lender. (Exhibit
                     10.4 to AIMCO's Current Report on Form 10-Q for quarter
                     ended March 31, 2000, is incorporated herein by this
                     reference.) (d) Not applicable.


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         (d)         Not applicable.

         (g)         Not applicable.

         (h)         Not applicable.

         (z)(1)      Agreement of Joint Filing, dated May 15, 2000, among AIMCO,
                     AIMCO-GP and AIMCO OP.

Item 13.  Information Required by Schedule 13E-3.

                     Not applicable.


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                                    SIGNATURE

                  After due inquiry and to the best of my knowledge and belief,
I certify that the information set forth in this statement is true, complete and
correct.


Date May 15, 2000                                 AIMCO PROPERTIES, L.P.

                                                  By: AIMCO-GP, INC.
                                                      (General Partner)

                                                  By: /s/ Patrick J. Foye
                                                     --------------------------
                                                     Executive Vice President

                                                  AIMCO OP

                                                  By: /s/ Patrick J. Foye
                                                     --------------------------
                                                     Executive Vice President

                                                  AIMCO-GP, INC.

                                                  By: /s/ Patrick J. Foye
                                                     --------------------------
                                                     Executive Vice President


                                                  APARTMENT INVESTMENT
                                                  AND MANAGEMENT COMPANY

                                                  By: /s/ Patrick J. Foye
                                                     --------------------------
                                                     Executive Vice President



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                                  EXHIBIT INDEX




EXHIBIT NO.                   DESCRIPTION
- -----------                   -----------
               

    (a)(1)        Offer to Purchase, dated May 15, 2000

    (a)(2)(i)     Letter of Transmittal and related Instructions (Annex II to
                  Exhibit (a)(1).)

    (a)(2)(ii)    Acknowledgment and Agreement

    (a)(3)        Letter, dated May 15, 2000, from AIMCO OP to the limited
                  partners of the Partnership

    (b)(1)        Credit Agreement (Secured Revolving Credit Facility), dated as
                  of August 16, 1999, among AIMCO Properties, L.P., Bank of
                  America, Bank Boston, N.A., and First Union National Bank.
                  (Exhibit 10.1 to AIMCO's Current Report on Form 8-K, dated
                  August 16, 1999, is incorporated herein by this reference.)

    (b)(2)        Amended and Restated Credit Agreement, dated as of March 15,
                  2000, among AIMCO Properties, L.P., Bank of America, Bank
                  Boston, N.A., and First Union National Bank. (Exhibit 10.20 to
                  AIMCO Properties, L.P.'s Annual Report on Form 10-K for the
                  year ended December 31, 1999, is incorporated herein by this
                  reference.)

    (b)(3)        First Amendment to $345,000,000 Amended and Restated Credit
                  Agreement, dated as of April 14, 2000, among AIMCO Properties,
                  L.P., Bank of America, as Administrative Agent, and U.S. Bank
                  National Association, as Lender. (Exhibit 10.4 to AIMCO's
                  Current Report on Form 10-Q for quarter ended March 31, 2000,
                  is incorporated herein by this reference.)

    (d)           Not applicable.

    (g)           Not applicable.

    (h)           Not applicable.

    (z)(1)        Agreement of Joint Filing, dated May 15, 2000, among AIMCO,
                  AIMCO-GP and AIMCO OP.