<Page>
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- --------------------------------------------------------------------------------
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
------------------------
FORM 10-Q
<Table>
/X/ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
SECURITIES EXCHANGE ACT OF 1934 FOR THE QUARTERLY PERIOD
ENDED MARCH 31, 2002
/ / TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD
FROM TO
Commission File Number 1-7884
</Table>
------------------------
MESA ROYALTY TRUST
(Exact name of registrant as specified in its charter)
<Table>
TEXAS 74-6284806
(State of Incorporation (I.R.S. Employer
or Organization) Identification No.)
JPMORGAN CHASE BANK, TRUSTEE 78701
INSTITUTIONAL TRUST SERVICES (Zip Code)
700 LAVACA
AUSTIN, TEXAS
(Address of Principal Executive
Offices)
</Table>
512-479-2562
(Registrant's Telephone Number, Including Area Code)
------------------------
Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports) and (2) has been subject to such
filing requirements for the past 90 days. Yes /X/ No / /
Indicate the number of shares outstanding of each of the registrant's
classes of common stock, as of the latest practicable date.
As of April 24, 2002--1,863,590 Units of Beneficial Interest in Mesa Royalty
Trust.
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<Page>
PART I--FINANCIAL INFORMATION
ITEM 1. FINANCIAL STATEMENTS.
MESA ROYALTY TRUST
STATEMENTS OF DISTRIBUTABLE INCOME
(UNAUDITED)
<Table>
<Caption>
THREE MONTHS ENDED
MARCH 31,
---------------------
2002 2001
-------- ----------
Royalty income.............................................. $903,004 $3,830,016
Interest income............................................. 1,723 44,123
General and administrative expense.......................... (11,797) (5,934)
-------- ----------
Distributable income...................................... $892,930 $3,868,205
======== ==========
Distributable income per unit............................. $ 0.4791 $ 2.0757
======== ==========
</Table>
STATEMENTS OF ASSETS, LIABILITIES AND TRUST CORPUS
<Table>
<Caption>
MARCH 31, DECEMBER 31,
2002 2001
------------ ------------
(UNAUDITED)
ASSETS
Cash and short-term investments............................. $ 891,207 $ 1,167,273
Interest receivable......................................... 1,723 4,475
Net overriding royalty interest in oil and gas properties... 42,498,034 42,498,034
Accumulated amortization.................................... (31,882,883) (31,632,768)
------------ ------------
Total assets.............................................. $ 11,508,081 $ 12,037,014
============ ============
LIABILITIES AND TRUST CORPUS
Distributions payable....................................... $ 892,930 $ 1,171,748
Trust corpus (1,863,590 units of beneficial interest
authorized and outstanding)............................... 10,615,151 10,865,266
------------ ------------
Total liabilities and trust corpus........................ $ 11,508,081 $ 12,037,014
============ ============
</Table>
(The accompanying notes are an integral part of these financial statements.)
1
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MESA ROYALTY TRUST
STATEMENTS OF CHANGES IN TRUST CORPUS
(UNAUDITED)
<Table>
<Caption>
THREE MONTHS ENDED
MARCH 31,
-------------------------
2002 2001
----------- -----------
Trust corpus, beginning of period........................... $10,865,266 $11,861,903
Distributable income...................................... 892,930 3,868,205
Distributions to unitholders.............................. (892,930) (3,868,205)
Amortization of net overriding royalty interest........... (250,115) (196,820)
----------- -----------
Trust corpus, end of period................................. $10,615,151 $11,665,083
=========== ===========
</Table>
(The accompanying notes are an integral part of these financial statements.)
2
<Page>
MESA ROYALTY TRUST
NOTES TO FINANCIAL STATEMENTS
(UNAUDITED)
NOTE 1--TRUST ORGANIZATION
The Mesa Royalty Trust (the "Trust") was created on November 1, 1979 when
Mesa Petroleum Co. conveyed to the Trust a 90% net profits overriding royalty
interest (the "Royalty") in certain producing oil and gas properties located in
the Hugoton field of Kansas, the San Juan Basin field of New Mexico and Colorado
and the Yellow Creek field of Wyoming (collectively, the "Royalty Properties").
Mesa Petroleum Co. was the predecessor to Mesa Limited Partnership ("MLP"), the
predecessor to MESA Inc. On April 30, 1991, MLP sold its interests in the
Royalty Properties located in the San Juan Basin field to Conoco Inc.
("Conoco"). Conoco sold the portion of its interests in the San Juan Basin
Royalty Properties located in Colorado to MarkWest Energy Partners, Ltd.
(effective January 1, 1993) and Red Willow Production Company (effective
April 1, 1992). On October 26, 1994, MarkWest Energy Partners, Ltd. sold
substantially all of its interest in the Colorado San Juan Basin Royalty
Properties to Amoco Production Company ("Amoco"), a subsidiary of BP Amoco.
Until August 7, 1997, MESA Inc. operated the Hugoton Royalty Properties through
Mesa Operating Co., a wholly owned subsidiary of MESA Inc. On August 7, 1997,
MESA Inc. merged with and into Pioneer Natural Resources Company ("Pioneer"),
formerly a wholly owned subsidiary of MESA Inc., and Parker & Parsley Petroleum
Company merged with and into Pioneer Natural Resources USA, Inc. (successor to
Mesa Operating Co.), a wholly owned subsidiary of Pioneer ("PNR") (collectively,
the mergers are referred to herein as the "Merger"). Subsequent to the Merger,
the Hugoton Royalty Properties have been operated by PNR. The San Juan Basin
Royalty Properties located in New Mexico are operated by Conoco. The San Juan
Basin Royalty Properties located in Colorado are operated by Amoco. As used in
this report, PNR refers to the operator of the Hugoton Royalty Properties,
Conoco refers to the operator of the San Juan Basin Royalty Properties, other
than the portion of such properties located in Colorado, and Amoco refers to the
operator of the Colorado San Juan Basin Royalty Properties unless otherwise
indicated. The terms "working interest owner" and "working interest owners"
generally refer to the operators of the Royalty Properties as described above,
unless the context in which such terms are used indicates otherwise.
NOTE 2--BASIS OF PRESENTATION
The accompanying unaudited financial information has been prepared by
JPMorgan Chase Bank ("Trustee") in accordance with the instructions to
Form 10-Q. JPMorgan Chase Bank was formerly known as The Chase Manhattan Bank
and is the successor by mergers to the original name of the Trustee, Texas
Commerce Bank National Association. The Trustee believes such information
includes all the disclosures necessary to make the information presented not
misleading. The information furnished reflects all adjustments which are, in the
opinion of the Trustee, necessary for a fair presentation of the results for the
interim periods presented. The financial information should be read in
conjunction with the financial statements and notes thereto included in the
Trust's 2001 Annual Report on Form 10-K.
The Mesa Royalty Trust Indenture was amended in 1985, the effect of which
was an overall reduction of approximately 88.56% in the size of the Trust;
therefore, the Trust is now entitled to receive 90% of 11.44% of the net
proceeds for the preceding month. Generally, net proceeds means the excess of
the amounts received by the working interest owners from sales of oil and gas
from the Royalty Properties over operating and capital costs incurred.
3
<Page>
The financial statements of the Trust are prepared on the following basis:
(a) Royalty income recorded for a month is the amount computed and paid by
the working interest owners to the Trustee for such month rather than
either the value of a portion of the oil and gas produced by the working
interest owners for such month or the amount subsequently determined to
be the Trust's proportionate share of the net proceeds for such month;
(b) Interest income, interest receivable and distributions payable to
unitholders include interest to be earned on short-term investments from
the financial statement date through the next date of distribution;
(c) Trust general and administrative expenses, net of reimbursements, are
recorded in the month they accrue;
(d) Amortization of the net overriding royalty interests, which is
calculated on a unit-of-production basis, is charged directly to trust
corpus since such amount does not affect distributable income; and
(e) Distributions payable are determined on a monthly basis and are payable
to unitholders of record as of the last business day of each month or
such other day as the Trustee determines is required to comply with legal
or stock exchange requirements. However, cash distributions are made
quarterly in January, April, July and October, and include interest
earned from the monthly record dates to the date of distribution.
This basis for reporting distributable income is thought to be the most
meaningful because distributions to the unitholders for a month are based on net
cash receipts for such month. However, it will differ from the basis used for
financial statements prepared in accordance with accounting principles generally
accepted in the United States because under such accounting principles, royalty
income for a month would be based on net proceeds from production for such month
without regard to when calculated or received and interest income for a month
would be calculated only through the end of such month.
4
<Page>
ITEM 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
OF OPERATIONS.
NOTE REGARDING FORWARD-LOOKING STATEMENTS
This Form 10-Q includes "forward-looking statements" within the meaning of
Section 27A of the Securities Act of 1933, as amended, and Section 21E of the
Securities Exchange Act of 1934, as amended. All statements other than
statements of historical facts included in this Form 10-Q, including without
limitation the statements under "Management's Discussion and Analysis of
Financial Condition and Results of Operations" are forward-looking statements.
Although the Working Interest Owners have advised the Trust that they believe
that the expectations reflected in the forward-looking statements contained
herein are reasonable, no assurance can be given that such expectations will
prove to have been correct. Important factors that could cause actual results to
differ materially from expectations ("Cautionary Statements") are disclosed in
this Form 10-Q and in the Trust's Form 10-K, including under the section
"Business--Principal Trust Risk Factors". All subsequent written and oral
forward-looking statements attributable to the Trust or persons acting on its
behalf are expressly qualified in their entirety by the Cautionary Statements.
SUMMARY OF ROYALTY INCOME AND AVERAGE PRICES
(UNAUDITED)
Royalty income is computed after deducting the Trust's proportionate share
of capital costs, operating costs and interest on any cost carryforward from the
Trust's proportionate share of "Gross Proceeds," as defined in the Royalty
conveyance. The following summary illustrates the net effect of the components
of the actual Royalty computation for the periods indicated.
<Table>
<Caption>
THREE MONTHS ENDED MARCH 31,
---------------------------------------------------
2002 2001
------------------------ ------------------------
OIL, OIL,
CONDENSATE CONDENSATE
NATURAL AND NATURAL NATURAL AND NATURAL
GAS GAS LIQUIDS GAS GAS LIQUIDS
---------- ----------- ---------- -----------
The Trust's proportionate share of Gross
Proceeds(1).................................. $1,640,115 $451,499 $3,940,564 $836,005
Less the Trust's proportionate share of:
Capital costs recovered(2)................... (392,209) -- (159,733) --
Operating costs.............................. (723,248) (68,253) (701,202) (85,618)
Interest on cost carryforward................ (4,900) -- -- --
---------- -------- ---------- --------
Royalty income................................. $ 519,758 $383,246 $3,079,629 $750,387
========== ======== ========== ========
Average sales price............................ $ 2.36 $ 13.54 $ 5.44 $ 26.27
========== ======== ========== ========
(Mcf) (Bbls)
Net production volumes attributable to the
Royalty(3)................................... 220,409 28,300 565,823 28,563
========== ======== ========== ========
</Table>
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(1) Gross Proceeds from natural gas liquids attributable to the Hugoton and San
Juan Basin Properties are net of a volumetric in-kind processing fee
retained by PNR and Conoco, respectively.
5
<Page>
(2) Capital costs recovered represents capital costs incurred during the current
or prior periods to the extent that such costs have been recovered by the
working interest owners from current period Gross Proceeds. Cost
carryforward represents capital costs incurred during the current or prior
periods which will be recovered from future period Gross Proceeds. The cost
carryforward resulting from the Fruitland Coal drilling program was $277,814
and $504,411 at March 31, 2002 and March 31, 2001, respectively, and relates
solely to the San Juan Basin Colorado properties.
(3) Net production volumes attributable to the Royalty are determined by
dividing Royalty income by the average sales price received.
THREE MONTHS ENDED MARCH 31, 2002 AND 2001
The distributable income of the Trust for each period includes the royalty
income received from the working interest owners during such period, plus
interest income earned to the date of distribution. Trust administration
expenses are deducted in the computation of distributable income. Distributable
income for the quarter ended March 31, 2002 was $892,930, representing $.4791
per unit, compared to $3,868,205, representing $2.0757 per unit, for the first
quarter ended March 31, 2001. Based on 1,863,590 units outstanding for the
quarters ended March 31, 2002 and 2001, respectively, the per unit distributions
were as follows:
<Table>
<Caption>
2002 2001
-------- --------
January................................................... $ .0842 $ .5811
February.................................................. .1940 .6710
March..................................................... .2009 .8236
------- -------
$ .4791 $2.0757
======= =======
</Table>
HUGOTON FIELD
Natural gas and natural gas liquids from the Hugoton field and attributable
to the Royalty accounted for approximately 73% of the Royalty income of the
Trust during the first quarter of 2002.
PNR has advised the Trust that since June 1, 1995 natural gas produced from
the Hugoton field has generally been sold under short-term and multi-month
contracts at market clearing prices to multiple purchasers including Williams
Energy Supply ("WESCO"), Oneok Gas Marketing, Inc., Amoco Production Company and
Anadarko Energy Services, Inc. PNR has advised the Trust that it expects to
continue to market gas production from the Hugoton field under short-term and
multi-month contracts. Overall market prices received for natural gas from the
Hugoton Royalty Properties were lower in the first quarter of 2002 compared to
the first quarter of 2001.
In June 1994, PNR entered into a Gas Transportation Agreement ("Gas
Transportation Agreement") with Western Resources, Inc. ("WRI") for a primary
term of five years commencing June 1, 1995. This contract has been continued in
effect on a year-to-year basis being effective June 1, 2001. PNR has extended
the contract to June 1, 2002. Pursuant to the Gas Transportation Agreement, WRI
has agreed to compress and transport up to 160 MMcf per day of gas and redeliver
such gas to PNR at the inlet of PNR's Satanta Plant. PNR agreed to pay WRI a fee
of $0.06 per Mcf escalating 4% annually as of June 1, 1996. This Gas
Transportation Agreement was assigned to Midcontinent Market Center.
6
<Page>
Royalty income attributable to the Hugoton Royalty decreased to $656,107 in
the first quarter of 2002, from $2,023,291 in the first quarter of 2001 due to
lower prices received for production of natural gas and liquids from the Hugoton
Royalty Properties. The average price received in the first quarter of 2002 for
natural gas and natural gas liquids sold from the Hugoton Royalty Properties was
$2.33 per Mcf and $13.69 per barrel, respectively, compared to $5.39 per Mcf and
$24.88 per barrel, respectively, in the first quarter of 2001. Net production
attributable to the Hugoton Royalty decreased to 181,634 Mcf of natural gas and
17,013 barrels of natural gas liquids in the first quarter of 2002 from 294,498
Mcf of natural gas and 17,522 barrels of natural gas liquids in the first
quarter of 2001 which is solely related to the lower prices.
Allowable rates of production in the Hugoton field are set by the Kansas
Corporation Commission (the "KCC") based on the level of market demand. The KCC
has set the Hugoton field allowable for the period April 1, 2002 through
September 30, 2002, at 141 Bcf of gas, compared with 156.2 Bcf of gas during the
same period last year.
SAN JUAN BASIN
Royalty income from the San Juan Basin Royalty Properties is calculated and
paid to the Trust on a state-by-state basis. Royalty income from the San Juan
Basin Royalty Properties located in the state of New Mexico was $246,897 during
the first quarter of 2002 as compared with royalty income of $1,806,725 in the
first quarter of 2001. The decrease in Royalty income was due primarily to
decreased natural gas and natural gas liquids prices in the first quarter of
2002. No royalty income was received from Amoco with respect to the San Juan
Basin Royalty Properties located in the state of Colorado for the first quarter
of 2002 and 2001, as costs associated with the Fruitland Coal drilling program
on such properties have not been fully recovered. Net production attributable to
the San Juan Basin Royalty was 38,775 Mcf of natural gas and 11,287 barrels of
natural gas liquids in the first quarter of 2002, compared to 271,325 Mcf of
natural gas and 11,041 barrels of natural gas liquids in the first quarter of
2001. The average price received in the first quarter of 2002 for natural gas
and natural gas liquids sold from the San Juan Basin Royalty Properties was
$2.49 per Mcf and $13.32 per barrel, respectively, compared to $5.50 per Mcf and
$28.48 per barrel during the same period in 2001.
The Trust's interest in the San Juan Basin was conveyed from PNR's working
interest in 31,328 net producing acres in northwestern New Mexico and
southwestern Colorado. The San Juan Basin-New Mexico reserves represent
approximately 52% of the Trust's reserves. Substantially all of the natural gas
produced from the San Juan Basin is currently being sold on the spot market. The
San Juan Basin Royalty Properties located in Colorado account for less than 5%
of the Trust's reserves.
No distributions related to the Colorado portion of the San Juan Basin
Royalty have been made since 1990, as the costs of the Fruitland Coal drilling
in Colorado have not yet been recovered.
Conoco has informed the Trust that it believes the production from the
Fruitland Coal formation will generally qualify for the tax credits provided
under Section 29 of the Internal Revenue Code of 1986, as amended. Thus,
unitholders are potentially eligible to claim their share of the tax credit
attributable to this qualifying production. Each unitholder should consult his
tax advisor regarding the limitations and requirements for claiming this tax
credit.
ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK.
The Trust does not utilize market risk sensitive instruments. However, see
the discussion of marketing by the working interest owners above.
7
<Page>
PART II--OTHER INFORMATION
ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K.
(A) EXHIBITS
(Asterisk indicates exhibit previously filed with the Securities and
Exchange Commission and incorporated herein by reference. JPMorgan Chase Bank
was formerly known as The Chase Manhattan Bank and is successor by mergers to
the original name of the Trustee, Texas Commerce Bank National Association).
<Table>
<Caption>
SEC FILE
OR
REGISTRATION EXHIBIT
NUMBER NUMBER
------------ --------
4(a) * Mesa Royalty Trust Indenture between Mesa Petroleum Co. and
Texas Commerce Bank National Association, as Trustee, dated
November 1, 1979............................................ 2-65217 1(a)
4(b) * Overriding Royalty Conveyance between Mesa Petroleum Co. and
Texas Commerce Bank, as Trustee, dated November 1, 1979..... 2-65217 1(b)
4(c) * First Amendment to the Mesa Royalty Trust Indenture dated as
of March 14, 1985 (Exhibit 4(c) to Form 10-K for year ended
December 31, 1984 of Mesa Royalty Trust).................... 1-7884 4(c)
4(d) * Form of Assignment of Overriding Royalty Interest, effective
April 1, 1985, from Texas Commerce Bank National
Association, as Trustee, to MTR Holding Co. (Exhibit 4(d) to
Form 10-K for year ended December 31, 1984 of Mesa Royalty
Trust)...................................................... 1-7884 4(d)
4(e) * Purchase and Sale Agreement, dated March 25, 1991, by and
among Mesa Limited Partnership, Mesa Operating Limited
Partnership and Conoco, as amended on April 30, 1991
(Exhibit 4(e) to Form 10-K for year ended December 31, 1991
of Mesa Royalty Trust)...................................... 1-7884 4(e)
</Table>
(B) REPORTS ON FORM 8-K
No reports on Form 8-K were filed with the Securities and Exchange
Commission by the Trust during the first quarter of 2002.
8
<Page>
SIGNATURES
PURSUANT TO THE REQUIREMENTS OF THE SECURITIES EXCHANGE ACT OF 1934, THE
REGISTRANT HAS DULY CAUSED THIS REPORT TO BE SIGNED ON ITS BEHALF BY THE
UNDERSIGNED, THEREUNTO DULY AUTHORIZED.
<Table>
MESA ROYALTY TRUST
By: JPMORGAN CHASE BANK,
as Trustee
By: /s/ MIKE ULRICH
-----------------------------------------
Mike Ulrich
VICE PRESIDENT
</Table>
Date: April 24, 2002
The Registrant, Mesa Royalty Trust, has no principal executive officer,
principal financial officer, board of directors or persons performing similar
functions. Accordingly, no additional signatures are available and none have
been provided.
9