<PAGE>
                                                                   Exhibit 4.2.6


      SIXTH SUPPLEMENTAL INDENTURE, dated as of May 14, 2004 (the "Sixth
Supplemental Indenture") between Meritage Corporation, a corporation organized
under the laws of the State of Maryland (the "Issuer"), the Guarantors named
therein, Meritage Homes of Colorado, Inc., an Arizona corporation (the
"Additional Guarantor") and Wells Fargo Bank, National Association, as trustee
(the "Trustee"), under the Indenture (as defined below). Capitalized terms used
and not defined herein shall have the same meanings given in the Indenture
unless otherwise indicated.

      WHEREAS, the Issuer, the Guarantors thereto and the Trustee are parties to
that certain Indenture dated as of May 30, 2001 (the "Indenture") pursuant to
which the Company issued its 9 -3/4% Senior Notes 2011 (the "Notes") and the
Guarantors guaranteed the obligations of the Issuer under the Indenture and the
Notes;

      WHEREAS, pursuant to Section 4.13 of the Indenture, if the Issuer acquires
or creates any additional subsidiary which is a Restricted Subsidiary, each such
subsidiary shall execute and deliver a supplemental indenture pursuant to which
such subsidiary shall unconditionally guaranty the Issuer's obligations under
the Notes;

      WHEREAS, the Issuer, the Guarantors thereto, Hulen Park Venture, LLC,
Meritage Holdings, L.L.C. and the Trustee are parties to that First Supplemental
Indenture, dated as of September 20, 2001 (the "First Supplemental Indenture")
pursuant to which Hulen Park Venture, LLC and Meritage Holdings, L.L.C. were
added as Guarantors;

      WHEREAS, the Issuer, the Guarantors thereto, MTH Homes-Texas, L.P.,
MTH-Texas GP II, Inc., MTH-Texas LP II, Inc. and the Trustee are parties to that
Second Supplemental Indenture, dated as of July 12, 2002 (the "Second
Supplemental Indenture") pursuant to which MTH Homes-Texas, L.P., MTH-Texas GP
II, Inc. and MTH-Texas LP II, Inc. were added as Guarantors;

      WHEREAS, the Issuer, the Guarantors thereto, MTH-Homes Nevada, Inc. and
the Trustee are parties to that Third Supplemental Indenture, dated as of
October 21, 2002 (the "Third Supplemental Indenture") pursuant to which
MTH-Homes Nevada, Inc. was added as a Guarantor;

      WHEREAS, the Issuer, the Guarantors thereto, MTH Cavalier, LLC and the
Trustee are parties to that Fourth Supplemental Indenture, dated as of February
19, 2003 (the "Fourth Supplemental Indenture") pursuant to which MTH Cavalier,
LLC was added as a Guarantor;

      WHEREAS, the Issuer, the Guarantors thereto, Mission Royale Golf Course,
LLC and Legacy-Hammonds Materials, L.P. are parties to that Sixth Supplemental
Indenture, dated as of August 22, 2003 (the "Fifth Supplemental Indenture")
pursuant to which Mission Royale Golf Course, LLC and Legacy-Hammonds Materials,
L.P. were added as Guarantors;

      WHEREAS, the Additional Guarantor is a Restricted Subsidiary of the
Issuer;

      WHEREAS, the Issuer and the Trustee desire to have the Additional
Guarantor enter into this Sixth Supplemental Indenture and agree to guaranty the
obligations of the Issuer under the Indenture and the Notes and the Additional
Guarantor desires to enter into this Sixth Supplemental Indenture and to
guaranty the obligations of the Issuer under the Indenture and the Notes as of
such date;
<PAGE>
      WHEREAS, Section 8.01 of the Indenture provides that the Issuer, the
Guarantors and the Trustee may, without the written consent of the Holders of
the outstanding Notes, amend the Indenture as provided herein;

      WHEREAS, by entering into this Sixth Supplemental Indenture, the Issuer
and the Trustee have consented to amend the Indenture in accordance with the
terms and conditions herein;

      WHEREAS, each Guarantor hereby acknowledges and consents to amend the
Indenture in accordance with the terms and conditions herein; and

      WHEREAS, all acts and things prescribed by the Articles of Incorporation
and Bylaws (as now in effect) of the Additional Guarantor necessary to make this
Sixth Supplemental Indenture a valid instrument legally binding on the
Additional Guarantor for the purposes herein expressed, in accordance with its
terms, have been duly done and performed.

      NOW, THEREFORE, in consideration of the foregoing and for other good and
valuable consideration, the receipt of which is hereby acknowledged, the Issuer,
the Additional Guarantor and the Trustee hereby agree for the benefit of each
other and the equal and ratable benefit of the Holders of the Notes as follows:

      1. Additional Guarantor as Guarantor. As of the date hereof and pursuant
to this Sixth Supplemental Indenture, the Additional Guarantor shall become a
Guarantor under the definition of Guarantor in the Indenture in accordance with
the terms and conditions of the Indenture and shall assume all rights and
obligations of a Guarantor thereunder.

      2. Compliance with and Fulfillment of Condition of Section 4.13. The
execution and delivery of this Sixth Supplemental Indenture by the Additional
Guarantor (along with such documentation relating thereto as the Trustee shall
require) fulfills the obligations of the Issuer under Section 4.13 of the
Indenture.

      3. Construction. For all purposes of this Sixth Supplemental Indenture,
except as otherwise herein expressly provided or unless the context otherwise
requires: (i) the defined terms and expressions used herein shall have the same
meanings as corresponding terms and expressions used in the Indenture; and (ii)
the words "herein," "hereof" and "hereby" and other words of similar import used
in this Sixth Supplemental Indenture refer to this Sixth Supplemental Indenture
as a whole and not to any particular Section hereof.

      4. Trustee Acceptance. The Trustee accepts the amendment of the Indenture
effected by this Sixth Supplemental Indenture, as hereby amended, but only upon
the terms and conditions set forth in the Indenture, as hereby amended,
including the terms and provisions defining and limiting the liabilities and
responsibilities of the Trustee in the performance of its duties and obligations
under the Indenture, as hereby amended. Without limiting the generality of the
foregoing, the Trustee has no responsibility for the correctness of the recitals
of fact herein contained which shall be taken as the statements of each of the
Issuer and the Additional Guarantor, respectively, and makes no representations
as to the validity or enforceability against either the Issuer or the Additional
Guarantor.


                                      -2-
<PAGE>
      5. Indenture Ratified. Except as expressly amended hereby, the Indenture
is in all respects ratified and confirmed and all the terms, conditions and
provisions thereof shall remain in full force and effect.

      6. Holders Bound. This Sixth Supplemental Indenture shall form a part of
the Indenture for all purposes, and every Holder of the Notes heretofore or
hereafter authenticated and delivered shall be bound hereby.

      7. Successors and Assigns. This Sixth Supplemental Indenture shall be
binding upon and inure to the benefit of the parties hereto and their respective
successors and assigns.

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

      9. Governing Law. This Sixth Supplemental Indenture shall be governed by
and construed in accordance with the internal laws of the State of New York
without giving effect to principles of conflicts of laws.

      IN WITNESS WHEREOF, the Issuer, the Additional Guarantor and the Trustee
have caused this Sixth Supplemental Indenture to be duly executed as of the date
first above written.

                                    ISSUER:

                                    MERITAGE CORPORATION

                                    By:   /s/ Steven J. Hilton
                                          Steven J. Hilton
                                    Its:  Co-Chairman, Co-President and Co-Chief
                                          Executive Officer

                                    By:   /s/ Larry W. Seay
                                          Larry W. Seay
                                    Its:  Chief Financial Officer, Vice
                                          President-Finance and Secretary


                                      -3-
<PAGE>
                                    ADDITIONAL GUARANTOR:

                                    MERITAGE HOMES OF COLORADO, INC.

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-Chairman and CEO

                                    By:   /s/ Larry W. Seay
                                          Larry W. Seay
                                    Its:  Vice President-Secretary

                                    TRUSTEE:

                                    WELLS FARGO BANK, NATIONAL ASSOCIATION,
                                    as Trustee

                                    By:   /s/ Jeanie Mar

                                    Its:  Vice President

                                    GUARANTORS:

                                    MONTEREY HOMES ARIZONA, INC.

                                    By:   /s/ Larry W. Seay
                                          Name:  Larry W. Seay
                                          Title: Vice President-Secretary

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-CEO, President and Chief
                                                 Executive Officer

                                    MERITAGE PASEO CROSSING, LLC

                                    By:   Meritage Homes of Arizona, Inc., its
                                          Sole Member

                                    By:   /s/ Larry W. Seay
                                          Name:  Larry W. Seay
                                          Title: Vice President-Secretary

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-CEO and Chairman


                                      -4-
<PAGE>
                                    MONTEREY HOMES CONSTRUCTION, INC.

                                    By:   /s/ Larry W. Seay
                                          Name:  Larry W. Seay
                                          Title: Vice President-Secretary

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-CEO, President and Chief
                                                 Executive Officer

                                    MERITAGE PASEO CONSTRUCTION, LLC

                                    By:   Meritage Homes Construction, Inc.,
                                          its Sole Member

                                    By:   /s/ Larry W. Seay
                                          Name:  Larry W. Seay
                                          Title: Vice President-Secretary

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-CEO and Co-Chairman

                                    MERITAGE HOMES OF ARIZONA, INC.

                                    By:   /s/ Larry W. Seay
                                          Name:  Larry W. Seay
                                          Title: Vice President-Secretary

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-CEO and Co-Chairman

                                    MERITAGE HOMES CONSTRUCTION, INC.

                                    By:   /s/ Larry W. Seay
                                          Name:  Larry W. Seay
                                          Title: Vice President-Secretary

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-CEO and Co-Chairman


                                      -5-
<PAGE>
                                    MTH-TEXAS GP, INC.

                                    By:   /s/ Larry W. Seay
                                          Name:  Larry W. Seay
                                          Title: Vice President-Secretary

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-Chairman

                                    MTH-TEXAS LP, INC.

                                    By:   /s/ Larry W. Seay
                                          Name:  Larry W. Seay
                                          Title: Vice President-Secretary

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-Chairman

                                    LEGACY/MONTEREY HOMES L.P.

                                    By:   MTH-Texas GP, Inc., its General
                                          Partner

                                    By:   /s/ Larry W. Seay
                                          Name:  Larry W. Seay
                                          Title: Vice President-Secretary

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-Chairman

                                    MERITAGE HOMES OF CALIFORNIA, INC.

                                    By:   /s/ Larry W. Seay
                                          Name:  Larry W. Seay
                                          Title: Vice President-Secretary

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-CEO, President and Chief
                                                 Executive Officer


                                      -6-
<PAGE>
                                    HANCOCK-MTH BUILDERS, INC.

                                    By:   /s/ Larry W. Seay
                                          Name:  Larry W. Seay
                                          Title: Vice President-Secretary

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-Chairman and Co-CEO

                                    HANCOCK-MTH COMMUNITIES, INC.

                                    By:   /s/ Larry W. Seay
                                          Name:  Larry W. Seay
                                          Title: Vice President-Secretary

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-Chairman and Co-CEO

                                    LEGACY OPERATING COMPANY, L.P.

                                    By:   Meritage Holdings, L.L.C., its General
                                          Partner

                                    By:   Legacy/Monterey Homes L.P., its Sole
                                          Member

                                    By:   MTH-Texas GP, Inc., its General
                                          Partner

                                    By:   /s/ Steven J. Hilton
                                          Steven J. Hilton
                                    Its:  Co-Chairman

                                    By:   /s/ Larry W. Seay
                                          Larry W. Seay
                                    Its:  Vice President-Secretary


                                      -7-
<PAGE>
                                    HULEN PARK VENTURE, LLC

                                    By:   Legacy/Monterey Homes L.P., its Sole
                                          Member

                                    By:   MTH-Texas GP, Inc., its General
                                          Partner

                                    By:   /s/ Steven J. Hilton
                                          Steven J. Hilton
                                    Its:  Co-Chairman

                                    By:   /s/ Larry W. Seay
                                          Larry W. Seay
                                    Its:  Vice President-Secretary

                                    MERITAGE HOLDINGS, L.L.C.

                                    By:   Legacy/Monterey Homes L.P., its Sole
                                          Member

                                    By:   MTH-Texas GP, Inc., its General
                                          Partner

                                    By:   /s/ Steven J. Hilton
                                          Steven J. Hilton
                                    Its:  Co-Chairman

                                    By:   /s/ Larry W. Seay
                                          Larry W. Seay
                                    Its:  Vice President-Secretary

                                    MTH HOMES-TEXAS, L.P.

                                    By:   MTH-Texas GP II, Inc., its General
                                          Partner

                                    By:   /s/ Steven J. Hilton
                                          Steven J. Hilton
                                    Its:  Co-Chairman

                                    By:   /s/ Larry W. Seay
                                          Larry W. Seay
                                    Its:  Vice President-Secretary


                                      -8-
<PAGE>
                                    MTH-TEXAS GP II, INC.

                                    By:   /s/ Steven J. Hilton
                                          Steven J. Hilton
                                    Its:  Co-Chairman

                                    By:   /s/ Larry W. Seay
                                          Larry W. Seay
                                    Its:  Vice President-Secretary

                                    MTH-TEXAS LP II, INC.

                                    By:   /s/ Steven J. Hilton
                                          Steven J. Hilton
                                    Its:  Co-Chairman

                                    By:   /s/ Larry W. Seay
                                          Larry W. Seay
                                    Its:  Vice President-Secretary

                                    MTH-HOMES NEVADA, INC.

                                    By:   /s/ Steven J. Hilton
                                          Steven J. Hilton
                                    Its:  Co-Chairman and Chief Executive
                                          Officer

                                    By:   /s/ Larry W. Seay
                                          Larry W. Seay
                                    Its:  Vice President-Secretary

                                    MTH-CAVALIER, LLC

                                    By:   Monterey Homes Construction, Inc., its
                                          Sole Member

                                    By:   /s/ Larry W. Seay
                                          Name:  Larry W. Seay
                                          Title: Vice President-Secretary

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-CEO, President and Chief
                                                 Executive Officer


                                      -9-
<PAGE>
                                    MTH GOLF, LLC

                                    By:   Hancock-MTH Builders, Inc., its Sole
                                          Member

                                    By:   /s/ Larry W. Seay
                                          Name:  Larry W. Seay
                                          Title: Vice President-Secretary

                                    By:   /s/ Steven J. Hilton
                                          Name:  Steven J. Hilton
                                          Title: Co-Chairman and Co-CEO

                                    LEGACY-HAMMONDS MATERIALS, L.P.

                                    By:   Meritage Holdings, L.L.C., its General
                                          Partner

                                    By:   Legacy/Monterey Homes L.P., its Sole
                                          Member

                                    By:   MTH-Texas GP, Inc., its General
                                          Partner

                                    By:   /s/ Steven J. Hilton
                                          Steven J. Hilton
                                    Its:  Co-Chairman

                                    By:   /s/ Larry W. Seay
                                          Larry W. Seay
                                    Its:  Vice President-Secretary


                                      -10-