UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON D.C. 20549

                                 SCHEDULE 13D/A

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                               (AMENDMENT NO. 12)

                              THOUSAND TRAILS, INC.
                                (Name of Issuer)

                     COMMON STOCK, PAR VALUE $.01 PER SHARE
                         (Title of Class of Securities)

                                   917326-10-0
                                 (CUSIP Number)

                                 IRIS B. ROSKEN
                       CARL MARKS MANAGEMENT COMPANY, L.P.
                              135 EAST 57TH STREET
                               NEW YORK, NY 10022
                                 (212) 909-8405

                     (Name, Address and Telephone Number of
            Person Authorized to Receive Notices and Communications)

                                  JUNE 2, 2002

             (Date of Event which Requires Filing of this Statement)

     If the filing  person has  previously  filed a statement on Schedule 13G to
report the  acquisition  which is the  subject of this  Schedule  13D/A,  and is
filing this Schedule because of Rule 13d-1(b)(3) or (4), check the following box
[ ].

     Check the following  box if a fee is being paid with the statement  [ ]. (A
fee is not required only if the reporting person:  (1) has a previous  statement
on file reporting beneficial ownership of more than five percent of the class of
securities  described  in Item 1;  and (2) has  filed  no  amendment  subsequent
thereto reporting  beneficial  ownership of five percent or less of such class.)
(See Rule 13d-7.)

                                                              Page 1 of 10 pages

---------------------                                        -------------------
CUSIP NO. 917326-10-0             SCHEDULE 13D/A             Page 2  of 10 Pages
---------------------                                        -------------------

1   NAMES OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    Carl Marks Strategic Investments, L.P.
    --------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [ ]
                                                                       (b) [ ]
    --------------------------------------------------------------------------
3   SEC USE ONLY

    --------------------------------------------------------------------------
4   SOURCE OF FUNDS*

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

    --------------------------------------------------------------------------
6   CITZENSHIP OR PLACE OF ORGANIZATION

    Delaware
    --------------------------------------------------------------------------
                  7  SOLE VOTING POWER
                     3,153,848 shares**
     NUMBER OF       ---------------------------------------------------------
      SHARES      8  SHARED VOTING POWER
    BENEFICIALLY     -0-
     OWNED BY        ---------------------------------------------------------
       EACH       9  SOLE DISPOSITIVE POWER
     REPORTING       3,153,848 shares**
      PERSON         ---------------------------------------------------------
       WITH      10  SHARED DISPOSITIVE POWER
                     -0-
                     ---------------------------------------------------------
11  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    3,153,848 shares**
    --------------------------------------------------------------------------
12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES* [ ]


    --------------------------------------------------------------------------
13  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    45.6%
    --------------------------------------------------------------------------
14  TYPE OF REPORTING PERSON*

    PN
    --------------------------------------------------------------------------

---------------------                                        -------------------
CUSIP NO. 917326-10-0             SCHEDULE 13D/A             Page 3  of 10 Pages
---------------------                                        -------------------

1   NAMES OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    Carl Marks Strategic Investments II, L.P.
    --------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [ ]
                                                                       (b) [ ]
    --------------------------------------------------------------------------
3   SEC USE ONLY

    --------------------------------------------------------------------------
4   SOURCE OF FUNDS*

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

    --------------------------------------------------------------------------
6   CITZENSHIP OR PLACE OF ORGANIZATION

    Delaware
    --------------------------------------------------------------------------
                  7  SOLE VOTING POWER
                     -0-
     NUMBER OF       ---------------------------------------------------------
      SHARES      8  SHARED VOTING POWER
    BENEFICIALLY     -0-
     OWNED BY        ---------------------------------------------------------
       EACH       9  SOLE DISPOSITIVE POWER
     REPORTING       -0-
      PERSON         ---------------------------------------------------------
       WITH      10  SHARED DISPOSITIVE POWER
                     -0-
                     ---------------------------------------------------------
11  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    -0-
    --------------------------------------------------------------------------
12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES* [ ]


    --------------------------------------------------------------------------
13  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    -0-
    --------------------------------------------------------------------------
14  TYPE OF REPORTING PERSON*

    PN
    --------------------------------------------------------------------------

---------------------                                        -------------------
CUSIP NO. 917326-10-0             SCHEDULE 13D/A             Page 4  of 10 Pages
---------------------                                        -------------------

1   NAMES OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    Carl Marks Management Company, L.P.
    --------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [ ]
                                                                       (b) [ ]
    --------------------------------------------------------------------------
3   SEC USE ONLY

    --------------------------------------------------------------------------
4   SOURCE OF FUNDS*

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

    --------------------------------------------------------------------------
6   CITZENSHIP OR PLACE OF ORGANIZATION

    Delaware
    --------------------------------------------------------------------------
                  7  SOLE VOTING POWER
                     3,153,848 shares**
     NUMBER OF       ---------------------------------------------------------
      SHARES      8  SHARED VOTING POWER
    BENEFICIALLY     -0-
     OWNED BY        ---------------------------------------------------------
       EACH       9  SOLE DISPOSITIVE POWER
     REPORTING       3,153,848 shares**
      PERSON         ---------------------------------------------------------
       WITH      10  SHARED DISPOSITIVE POWER
                     -0-
                     ---------------------------------------------------------
11  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    3,153,848 shares**
    --------------------------------------------------------------------------
12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES* [ ]


    --------------------------------------------------------------------------
13  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    45.6%
    --------------------------------------------------------------------------
14  TYPE OF REPORTING PERSON*

    PN
    --------------------------------------------------------------------------

---------------------                                        -------------------
CUSIP NO. 917326-10-0             SCHEDULE 13D/A             Page 5  of 10 Pages
---------------------                                        -------------------

1   NAMES OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    Andrew M. Boas
    --------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [ ]
                                                                       (b) [ ]
    --------------------------------------------------------------------------
3   SEC USE ONLY

    --------------------------------------------------------------------------
4   SOURCE OF FUNDS*

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

    --------------------------------------------------------------------------
6   CITZENSHIP OR PLACE OF ORGANIZATION

    U.S.A.
    --------------------------------------------------------------------------
                  7  SOLE VOTING POWER
                     48,269 shares
     NUMBER OF       ---------------------------------------------------------
      SHARES      8  SHARED VOTING POWER
    BENEFICIALLY     3,156,436 shares**
     OWNED BY        ---------------------------------------------------------
       EACH       9  SOLE DISPOSITIVE POWER
     REPORTING       48,269 shares
      PERSON         ---------------------------------------------------------
       WITH      10  SHARED DISPOSITIVE POWER
                     3,156,436 shares**
                     ---------------------------------------------------------
11  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    3,204,705 shares**
    --------------------------------------------------------------------------
12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES* [ ]


    --------------------------------------------------------------------------
13  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    46.1%
    --------------------------------------------------------------------------
14  TYPE OF REPORTING PERSON*

    IN
    --------------------------------------------------------------------------

---------------------                                        -------------------
CUSIP NO. 917326-10-0             SCHEDULE 13D/A             Page 6  of 10 Pages
---------------------                                        -------------------

1   NAMES OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    Robert C. Ruocco
    --------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [ ]
                                                                       (b) [ ]
    --------------------------------------------------------------------------
3   SEC USE ONLY

    --------------------------------------------------------------------------
4   SOURCE OF FUNDS*

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

    --------------------------------------------------------------------------
6   CITZENSHIP OR PLACE OF ORGANIZATION

    U.S.A.
    --------------------------------------------------------------------------
                  7  SOLE VOTING POWER

     NUMBER OF       ---------------------------------------------------------
      SHARES      8  SHARED VOTING POWER
    BENEFICIALLY     3,153,848 shares**
     OWNED BY        ---------------------------------------------------------
       EACH       9  SOLE DISPOSITIVE POWER
     REPORTING
      PERSON         ---------------------------------------------------------
       WITH      10  SHARED DISPOSITIVE POWER
                     3,153,848 shares**
                     ---------------------------------------------------------
11  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    3,153,848 shares**
    --------------------------------------------------------------------------
12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES* [ ]


    --------------------------------------------------------------------------
13  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    45.6%
    --------------------------------------------------------------------------
14  TYPE OF REPORTING PERSON*

    IN
    --------------------------------------------------------------------------

---------------------                                        -------------------
CUSIP NO. 917326-10-0             SCHEDULE 13D/A             Page 7  of 10 Pages
---------------------                                        -------------------

1   NAMES OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    James F. Wilson
    --------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [ ]
                                                                       (b) [ ]
    --------------------------------------------------------------------------
3   SEC USE ONLY

    --------------------------------------------------------------------------
4   SOURCE OF FUNDS*

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

    --------------------------------------------------------------------------
6   CITZENSHIP OR PLACE OF ORGANIZATION

    U.S.A.
    --------------------------------------------------------------------------
                  7  SOLE VOTING POWER

     NUMBER OF       ---------------------------------------------------------
      SHARES      8  SHARED VOTING POWER
    BENEFICIALLY     3,153,848 shares**
     OWNED BY        ---------------------------------------------------------
       EACH       9  SOLE DISPOSITIVE POWER
     REPORTING
      PERSON         ---------------------------------------------------------
       WITH      10  SHARED DISPOSITIVE POWER
                     3,153,848 shares**
                     ---------------------------------------------------------
11  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    3,153,848 shares**
    --------------------------------------------------------------------------
12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES* [ ]


    --------------------------------------------------------------------------
13  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    45.6%
    --------------------------------------------------------------------------
14  TYPE OF REPORTING PERSON*

    IN
    --------------------------------------------------------------------------

ITEM 1.  SECURITY AND ISSUER

     This  Amendment  No. 12 to Schedule  13D relates to the Common  Stock,  par
value $.01 per share (the  "Common  Stock"),  issued by  Thousand  Trails,  Inc.
(formerly USTrails Inc.), a Delaware corporation (the "Company").  The principal
executive  offices of the Company are  located at 2711 LBJ  Freeway,  Suite 200,
Dallas, Texas 75234.

     This  Amendment to Schedule 13D is being filed pursuant to Section 13(d) of
the Securities  Exchange Act of 1934, as amended,  and the rules and regulations
promulgated  thereunder  (the "Exchange Act "). This Amendment  further amends a
Schedule 13D,  dated January 9, 1992, as previously  amended by Amendment No. 1,
dated February 7, 1992,  Amendment No. 2, dated November 7, 1992,  Amendment No.
3, dated March 9, 1993,  Amendment No. 4, dated June 30, 1994,  Amendment No. 5,
dated August 12, 1996, Amendment.  No. 6, dated December 12, 1996, Amendment No.
7, dated December 27, 1996,  Amendment No. 8, dated November 6, 1997,  Amendment
No. 9, dated  April 22,  1999,  Amendment  No.  10,  dated  July 26,  1999,  and
Amendment No. 11, dated March 8, 2001 (the "Original Schedule 13D" ).

     Except as amended hereby, the responses in the Original Schedule 13D remain
unchanged.

ITEM 2. IDENTITY AND BACKGROUND

     (a) In addition to the  Reporting  Persons  named in the Original 13D, this
Amendment to Schedule  13D is being filed by James F.  Wilson,  who is a general
partner of the General Partner in addition to Messrs. Boas and Ruocco.

     (b) The principal  business of Mr.  Wilson is acting as general  partner of
the General Partner. The business address of Mr. Wilson is 135 East 57th Street,
New York, New York 10022.

     (c) During the last five  years,  Mr.  Wilson has not been  convicted  in a
criminal proceeding (excluding traffic violations or similar misdemeanors).

     (d) During the last five years,  Mr. Wilson has not been 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  future  violations of, or prohibiting or mandating  activities
subject  to,  federal or state  securities  laws or finding any  violation  with
respect to such laws.

     (e) Mr. Wilson is a citizen of the United States of America.

                                      -8-

ITEM 5. INTEREST IN SECURITIES OF THE ISSUER

     (a) As of the  date  hereof,  Partnership  I owned  beneficially  3,153,848
shares of Common  Stock,  constituting  approximately  45.6% of the  outstanding
shares.  In its capacity as general partner of Partnership I, such shares may be
deemed also owned  beneficially by the General Partner and, in their capacity as
general partners of the General Partner, by Messrs. Boas, Ruocco and Wilson.

     As of  the  date  hereof  the  Reporting  Persons  owned  beneficially  the
following  respective  aggregate  amounts  and  approximate  percentages  of the
outstanding shares of Common Stock: (i) Partnership I, 3,153,848 shares (45.6%);
(ii) the General Partner,  3,153,848 shares (45.6%);  (iii) Mr. Boas,  3,204,705
shares,  including  options to purchase 36,700 shares (46.1%);  and (iv) each of
Messrs.  Ruocco and Wilson,  3,153,848 shares (45.6%).  Partnership II no longer
owns any shares of Common Stock.

     (c) On June 2, 2002,  Partnership  II completed  the sale to the Company of
1,140,481 shares of Common Stock, at a price (net) of $8.41 per share,  pursuant
to the Company's tender offer made to all shareholders of the Company.

     Except as  aforesaid,  or as previously  reported in the Original  Schedule
13D, no  transactions  in the Common Stock were effected by any of the Reporting
Persons within the past sixty (60) days.

ITEM 6. CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT TO
        SECURITIES OF THE ISSUER

     Reference  is made to the Offer to  Purchase of the  Company,  dated May 1,
2002 (filed as Exhibit  (a)(1)(A) to the Schedule TO of the Company,  filed with
the  Commission  on or about May 1,  2002) for a  description  of the  Company's
tender  offer for Common  Stock and  certain  matters in  connection  therewith,
including the agreement of Partnership II to tender its shares.

                                      -9-

                                   SIGNATURES

     After  reasonable  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: June 18, 2002


                                     CARL MARKS STRATEGIC INVESTMENTS, L.P.
                                     By: Carl Marks Management Company, L.P.,
                                         General Partner


                                     By: /s/ Andrew M. Boas
                                         ---------------------------------------
                                         Andrew M. Boas, a General Partner


                                     CARL MARKS STRATEGIC INVESTMENTS II, L.P.
                                     By: Carl Marks Management Company, L.P.,
                                         General Partner


                                     By: /s/ Andrew M. Boas
                                         ---------------------------------------
                                         Andrew M. Boas, a General Partner


                                     CARL MARKS MANAGEMENT COMPANY, L.P.

                                     By: /s/ Andrew M. Boas
                                         ---------------------------------------
                                         Andrew M. Boas, a General Partner


                                         /s/ Andrew M. Boas
                                         ---------------------------------------
                                         ANDREW M. BOAS


                                         /s/ Robert C. Ruocco
                                         ---------------------------------------
                                         ROBERT C. RUOCCO


                                         /s/ James F. Wilson
                                         ---------------------------------------
                                         JAMES F. WILSON

                                      -10-