<PAGE>   1
                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    Form 10-Q

              [X] Quarterly Report Pursuant to Section 13 or 15(d)
                     of the Securities Exchange Act of 1934
                  For the quarterly period ended March 31, 2001

                                       or

              [ ] 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: 1-11608

                      WILLIAMS COAL SEAM GAS ROYALTY TRUST
             (Exact name of registrant as specified in its charter)


<TABLE>
<S>                                                 <C>
                Delaware                                75-6437433
      (State or other jurisdiction                   (I.R.S. Employer
           of incorporation or                      Identification No.)
              organization)
</TABLE>


                                 Trust Division
                              Bank of America, N.A.
                                 901 Main Street
                                   17th Floor
                               Dallas, Texas 75202
                    (Address of principal executive offices)
                                   (Zip code)

                                 (214) 209-2400
              (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
                                              ---    ---

         Number of units of beneficial interest outstanding at May 1, 2001:
9,700,000.
<PAGE>   2
                         PART I - FINANCIAL INFORMATION

Item 1.  Financial Statements.

         The financial statements included herein have been prepared by Bank of
America, N.A., as Trustee (the "Trustee") of Williams Coal Seam Gas Royalty
Trust (the "Trust"), pursuant to the rules and regulations of the Securities and
Exchange Commission. Certain information and footnote disclosures normally
included in annual financial statements have been condensed or omitted pursuant
to such rules and regulations, although the Trustee believes that the
disclosures are adequate to make the information presented not misleading. It is
suggested that these condensed financial statements be read in conjunction with
the financial statements and notes thereto included in the Trust's Annual Report
on Form 10-K for the year ended December 31, 2000 (the "2000 Annual Report").
The December 31, 2000 balance sheet is derived from the audited balance sheet of
that date. In the opinion of the Trustee, all adjustments, consisting only of
normal recurring adjustments, necessary to present fairly the assets,
liabilities and trust corpus of the Trust as of March 31, 2001, and the
distributable income and the changes in trust corpus for the three-month periods
ended March 31, 2001 and 2000, have been included. The distributable income for
such interim periods is not necessarily indicative of the distributable income
for the full year.

         The financial statements as of March 31, 2001 and for the three-month
periods ended March 31, 2001 and 2000 included herein have been reviewed by
Ernst & Young LLP, independent public accountants, as stated in their report
appearing herein.

                                        2
<PAGE>   3
                     INDEPENDENT ACCOUNTANTS' REVIEW REPORT

Bank of America, N.A.,
         as Trustee of Williams Coal Seam Gas Royalty Trust

We have reviewed the accompanying condensed statement of assets, liabilities and
trust corpus of the Williams Coal Seam Gas Royalty Trust as of March 31, 2001,
and the related condensed statements of distributable income and changes in
trust corpus for the three-month periods ended March 31, 2001 and 2000. These
financial statements are the responsibility of the Trustee.

We conducted our reviews in accordance with standards established by the
American Institute of Certified Public Accountants. A review of interim
financial information consists principally of applying analytical procedures to
financial data, and making inquiries of persons responsible for financial and
accounting matters. It is substantially less in scope than an audit conducted in
accordance with auditing standards generally accepted in the United States,
which will be performed for the full year with the objective of expressing an
opinion regarding the financial statements taken as a whole. Accordingly, we do
not express such an opinion.

As described in Note 2 to the financial statements, these financial statements
have been prepared on a modified cash basis of accounting, which is a
comprehensive basis of accounting other than accounting principles generally
accepted in the United States.

Based on our reviews, we are not aware of any material modifications that should
be made to the accompanying condensed financial statements referred to above for
them to be in conformity with the basis of accounting described in Note 2.

We have previously audited, in accordance with auditing standards generally
accepted in the United States, the statement of assets, liabilities and trust
corpus of the Williams Coal Seam Gas Royalty Trust as of December 31, 2000, and
the related statements of distributable income and changes in trust corpus for
the year then ended (not presented herein) and in our report dated March 26,
2001, we expressed an unqualified opinion on those financial statements. In our
opinion, the information set forth in the accompanying condensed statement of
assets, liabilities and trust corpus as of December 31, 2000, is fairly stated,
in all material respects, in relation to the statement of assets, liabilities
and trust corpus from which it has been derived.


                                                 Ernst & Young LLP



Tulsa, Oklahoma
May 14, 2001

                                        3
<PAGE>   4
WILLIAMS COAL SEAM GAS ROYALTY TRUST

CONDENSED STATEMENTS OF ASSETS, LIABILITIES AND TRUST CORPUS
(UNAUDITED)

<TABLE>
<CAPTION>
                                           March 31,         December 31,
ASSETS                                       2001               2000
------                                       ----               ----
<S>                                      <C>                <C>
Current Assets -
        cash and cash equivalents        $    54,391        $    97,569
Royalty interests in oil
        and gas properties
        (less accumulated
        amortization of
        109,934,593 at
        March 31, 2001
        and $107,920,958 at
        December 31, 2000)                28,632,070         30,645,705
                                         -----------        -----------

TOTAL ASSETS                             $28,686,461        $30,743,274
                                         ===========        ===========


LIABILITIES AND TRUST CORPUS

Current Liabilities -
        trust expenses payable           $   106,798        $    73,008

Trust corpus -
        9,700,000 units of
        beneficial interest
        authorized and
        outstanding                       28,579,663         30,670,266
                                         -----------        -----------

TOTAL LIABILITIES
        AND TRUST CORPUS                 $28,686,461        $30,743,274
                                         ===========        ===========
</TABLE>


The accompanying notes are an integral part of these financial statements. See
accountants' review report.


                                        4
<PAGE>   5
WILLIAMS COAL SEAM GAS ROYALTY TRUST

CONDENSED STATEMENTS OF DISTRIBUTABLE INCOME (UNAUDITED)

<TABLE>
<CAPTION>
                                 THREE MONTHS      THREE MONTHS
                                     ENDED             ENDED
                                March 31, 2001    March 31, 2000
                                --------------    --------------
<S>                             <C>               <C>
Royalty income                    $5,818,139        $ 3,927,382
Interest income                       21,734             15,327
                                  ----------        -----------
                                   5,839,873          3,942,709

General and administrative
        expenses                     212,969           (204,428)
                                  ----------        -----------
Distributable income              $5,626,904        $ 3,728,281
                                  ==========        ===========
Distributable income
        per unit
        (9,700,000 units)         $      .58        $       .39
                                  ==========        ===========
</TABLE>


The accompanying notes are an integral part of these financial statements. See
accountants' review report.


                                        5
<PAGE>   6
WILLIAMS COAL SEAM GAS ROYALTY TRUST

CONDENSED STATEMENTS OF CHANGES IN TRUST CORPUS (UNAUDITED)


<TABLE>
<CAPTION>
                                     THREE MONTHS         THREE MONTHS
                                        ENDED                ENDED
                                    March 31, 2001       March 31, 2000
                                    --------------       --------------
<S>                                 <C>                  <C>
Trust corpus,
        beginning of period         $ 30,670,266         $ 40,198,727
Amortization of royalty
        interests                     (2,013,635)          (2,521,841)
Distributable income                   5,626,904            3,738,281
Distributions to unitholders          (5,703,872)          (3,907,704)
                                    ------------         ------------
Trust corpus, end
        of period                   $ 28,579,663         $ 37,507,463
                                    ============         ============
Distributions per unit
        (9,700,000 units)           $        .59         $        .40
                                    ============         ============
</TABLE>

The accompanying notes are an integral part of these financial statements. See
accountants' review report.


                                        6
<PAGE>   7
WILLIAMS COAL SEAM GAS ROYALTY TRUST

NOTES TO FINANCIAL STATEMENTS (UNAUDITED)


1.       TRUST ORGANIZATION AND PROVISIONS

         Williams Coal Seam Gas Royalty Trust (the "Trust") was formed as a
Delaware business trust pursuant to the terms of the Trust Agreement of Williams
Coal Seam Gas Royalty Trust (as amended, the "Trust Agreement") entered into
effective as of December 1, 1992 by and among Williams Production Company, a
Delaware corporation ("WPC"), as trustor, The Williams Companies, Inc., a
Delaware corporation ("Williams"), and Bank of America, N.A., as successor to
NationsBank, N.A., a national banking association (the "Trustee"), and Chemical
Bank Delaware, a Delaware banking corporation (the "Delaware Trustee"), as
trustees. The trustees are independent financial institutions.

         The Trust was formed to acquire and hold certain net profits interests
(the "Royalty Interests") in proved natural gas properties located in the San
Juan Basin of New Mexico and Colorado (the "Underlying Properties") owned at the
time of the Trust's formation by WPC. The Trust was initially created effective
as of December 1, 1992 with a $100 contribution by WPC. On January 21, 1993, the
Royalty Interests were conveyed to the Trust by WPC pursuant to the Net Profits
Conveyance (the "Conveyance") dated effective as of October 1, 1992 by and among
WPC, Williams, the Trustee and the Delaware Trustee, in consideration for all
the 9,700,000 authorized units of beneficial interest in the Trust ("Units").
WPC transferred its Units by dividend to its parent, Williams, which sold an
aggregate of 5,980,000 Units to the public through various underwriters in
January and February 1993 (the "Public Offering"). Subsequently, Williams sold
to the public an additional 151,209 Units. During the second quarter of 1995
Williams transferred its remaining Units to Williams Holdings of Delaware, Inc.
("WHD"), a separate holding company for Williams's non-regulated businesses.
Effective July 31, 1999, WHD was merged into Williams, and by operation of the
merger Williams assumed all assets, liabilities and obligations of WHD,
including without limitation ownership of WHD's Units. Effective August 11,
2000, Williams sold its Units to Quatro Finale IV LLC, a Delaware limited
liability company ("QFIV"), in a privately negotiated transaction. Williams has
agreed to hold the transferred Units as nominee for QFIV. Williams retained the
voting rights and retained a "call" option on the transferred Units, and QFIV
was granted a "put" option on the Units. Substantially all of the production
attributable to the Underlying Properties is from the Fruitland coal formation
and constitutes "coal seam" gas that entitles the owners of such production,
provided certain requirements are met, to tax credits for Federal income tax
purposes pursuant to Section 29 of the Internal Revenue Code of 1986, as
amended. Effective May 1, 1997, WPC transferred the Underlying Properties,
subject to and burdened by the Royalty Interests, to Quatro Finale LLC, a
non-affiliated Delaware limited liability company. Ownership of the Underlying
Properties reverted back to WPC effective February 1, 2001 under the terms of
the May 1, 1997 transaction. Pursuant to a Purchase and Sale Agreement dated
March 14, 2001 (the "2001 Transaction Agreement"), and effective March 1, 2001,
WPC sold the Underlying Properties subject to and burdened by the Royalty
Interests to Quatro Finale V LLC, a non-affiliated Delaware limited liability
company (the "2001 Transaction").

                                        7
<PAGE>   8
        As used in this Report, the term "Quatro Finale" generally refers to
either of Quatro Finale LLC or Quatro Finale V LLC that at the time in question
was or is the owner of the Underlying Properties. Consequently, unless otherwise
dictated by context, "Quatro Finale" generally means (a) with respect to the
period May 1, 1997 until February 1, 2001, Quatro Finale LLC (which entity
acquired and owned the Underlying Properties effective from May 1, 1997 until
February 1, 2001), and (b) with respect to the period from and after March 1,
2001, Quatro Finale V LLC (which entity acquired and has owned the Underlying
Properties effective and since March 1, 2001). With respect to the ownership of
the Underlying Properties for any period prior to May 1, 1997, and for the
period from February 1 through February 28, 2001, references herein to Quatro
Finale should be deemed to refer to WPC.

        The Trustee has the power to collect and distribute the proceeds
received by the Trust and to pay Trust liabilities and expenses. The Delaware
Trustee has only such powers as are set forth in the Trust Agreement and is not
empowered to otherwise manage or take part in the business of the Trust. The
Royalty Interests are passive in nature and neither the Delaware Trustee nor the
Trustee has any control over or any responsibility relating to the operation of
the Underlying Properties.

        The Trust will terminate no later than December 31, 2012, subject to
earlier termination under certain circumstances described in the Trust Agreement
(the "Termination Date"). Cancellation of the Trust will occur on or following
the Termination Date when all Trust assets have been sold and the net proceeds
therefrom distributed to Unitholders.

        The only assets of the Trust, other than cash and cash equivalents being
held for the payment of expenses and liabilities and for distribution to
Unitholders, are the Royalty Interests. The Royalty Interests consist primarily
of a net profits interest (the "NPI") in the Underlying Properties. From the
inception of the Trust until the fourth quarter of 2000, the NPI generally
entitled the Trust to receive 81 percent of the NPI Net Proceeds, as defined
below, attributable to (i) gas produced and sold from Quatro Finale's net
revenue interests (working interests less lease burdens) in the properties in
which Quatro Finale has a working interest (the "WI Properties") and (ii) the
revenue stream received by Quatro Finale attributable to its 35 percent net
profits interest in 5,348 gross acres in La Plata County, Colorado (the "Farmout
Properties"). The Royalty Interests also include a 20 percent interest in Quatro
Finale's Infill Net Proceeds, as defined below, from the sale of production if
well spacing rules are effectively modified and additional wells are drilled on
producing drilling blocks on the WI Properties (the "Infill Wells") during the
term of the Trust. No Infill Wells have been drilled on the WI Properties to
date. "NPI Net Proceeds" consists generally of the revenue stream received by
Quatro Finale from its 35 percent net profits interest in the Farmout
Properties, plus the aggregate proceeds attributable to Quatro Finale's net
revenue interest, based on the price paid at or in the vicinity of the wellhead
(the "Wellhead"), of gas produced from the WI Properties, less Quatro Finale's
share of certain taxes and costs. "Infill Net Proceeds" consists generally of
the aggregate proceeds, based on the price at the Wellhead, of gas produced from
Quatro Finale's net revenue interest in any Infill Wells less certain taxes and
costs. The complete definitions of NPI Net Proceeds and Infill Net Proceeds are
set forth in the Conveyance. The NPI percentage was subject to permanent
reduction under certain conditions as described under "Item 1 - Financial
Statements, Note 7 - NPI Percentage Reduction." A permanent downward adjustment
of the NPI percentage from 81 percent to 60 percent occurred during the fourth
quarter of the year 2000. Pursuant to the Conveyance, the NPI percentage is not
subject to further reduction or other adjustment regardless


                                        8
<PAGE>   9
of the future amount of cumulative production or the achieved internal rate of
return. Thus, the percentage of NPI Net Proceeds which the Trust is entitled to
receive was permanently reduced to 60 percent in the fourth quarter of 2000, and
Quatro Finale's retained percentage of NPI Net Proceeds was correspondingly
increased from 19 percent to 40 percent. See "Item 1 -- Financial Statements,
Note 7 -- NPI Percentage Reduction" below for detailed information about the NPI
percentage reduction.

2.       BASIS OF ACCOUNTING

         The financial statements of the Trust are prepared on a modified cash
basis and are not intended to present financial position and results of
operations in conformity with accounting principles generally accepted in the
United States ("GAAP"). Preparation of the Trust's financial statements on such
basis includes the following:

         Revenues are recognized in the period in which amounts are received by
         the Trust. General and administrative expenses are recognized on an
         accrual basis.

         Amortization of the Royalty Interests is calculated on a
         unit-of-production basis and charged directly to trust corpus.

         Distributions to Unitholders are recorded when declared by the Trustee
         (see "Item 1 - Financial Statements, Note 4 - Distributions to
         Unitholders").

         The financial statements of the Trust differ from financial statements
prepared in accordance with GAAP because royalty income is not accrued in the
period of production and amortization of the Royalty Interests is not charged
against operating results.

3.       FEDERAL INCOME TAXES

         The Trust is a grantor trust for Federal income tax purposes. As a
grantor trust, the Trust will not be required to pay Federal or state income
taxes. Accordingly, no provision for income taxes has been made in these
financial statements.

         Because the Trust will be treated as a grantor trust, and because a
Unitholder will be treated as directly owning an interest in the Royalty
Interests, each Unitholder will be taxed directly on his per Unit pro rata share
of income attributable to the Royalty Interests consistent with the Unitholder's
method of accounting and without regard to the taxable year or accounting method
employed by the Trust.

         Production from coal seam gas wells drilled after December 31, 1979 and
prior to January 1, 1993, qualifies for the Federal income tax credit for
producing nonconventional fuels under Section 29 of the Internal Revenue Code.
This tax credit is calculated annually based on each year's qualified production
through the year 2002. Such credit, based on the Unitholder's pro rata share of
qualifying production, may not reduce his regular tax liability (after the
foreign tax credit and certain other non-refundable credits) below his
alternative minimum tax. Any part of the Section 29 credit


                                        9
<PAGE>   10
not allowed for the tax year solely because of this limitation is subject to
certain carryover provisions. Each Unitholder should consult his tax advisor
regarding Trust tax compliance matters.

4.       DISTRIBUTIONS TO UNITHOLDERS

         The Trustee determines for each quarter the amount of cash available
for distribution to Unitholders. Such amount (the "Quarterly Distribution
Amount") is an amount equal to the excess, if any, of the cash received by the
Trust, on or prior to the last day of the month following the end of each
calendar quarter from the Royalty Interests, plus, with certain exceptions, any
other cash receipts of the Trust during such quarter, over the liabilities of
the Trust paid during such quarter, subject to adjustments for changes made by
the Trustee during such quarter in any cash reserves established for the payment
of contingent or future obligations of the Trust.

         The Quarterly Distribution Amount for each quarter is payable to
Unitholders of record on the 45th day following the end of such calendar quarter
unless such day is not a business day in which case the record date is the next
business day thereafter. The Trustee distributes the Quarterly Distribution
Amount within 60 days after the end of each calendar quarter to each person who
was a Unitholder of record on the associated record date, together with interest
estimated to be earned on such amount from the date of receipt thereof by the
Trustee to the payment date.

         In addition to the regular quarterly distributions, under certain
circumstances specified in the Trust Agreement (such as upon a purchase price
adjustment, if any, or pursuant to the sale of a Royalty Interest), the Trust
would make a special distribution (a "Special Distribution Amount"). A Special
Distribution Amount would be made when amounts received by the Trust under such
circumstances aggregated in excess of $9,000,000. The record date for a Special
Distribution Amount will be the 15th day following receipt of amounts
aggregating a Special Distribution Amount by the Trust (unless such day is not a
business day in which case the record date will be the next business day
thereafter) unless such day is within 10 days of the record date for a Quarterly
Distribution Amount in which case the record date will be the date as is
established for the next Quarterly Distribution Amount. Distribution to
Unitholders of a Special Distribution Amount will be made no later than 15 days
after the Special Distribution Amount record date.

5.       SUBSEQUENT EVENTS

         Subsequent to March 31, 2001, the Trust declared the following
distribution:

<TABLE>
<CAPTION>
              Quarterly
               Record                     Payment             Distribution
                Date                       Date                 per Unit
                ----                       ----                 --------
<S>                                    <C>                    <C>
            May 15, 2001               May 30, 2001             $ .893012
</TABLE>

         The distribution per unit increased from $.588028 in the first quarter
of 2001 to $.893012 in the second quarter of 2001. The increase in distributions
was mainly the result of higher natural gas prices at the beginning of the year.


                                       10
<PAGE>   11
6.       CONTINGENCIES

         WPX Gas Resources Company ("WPX Gas Resources", as successor in
interest to Williams Gas Marketing Company) purchases natural gas produced from
the WI Properties (except for certain small volumes) at the wellhead under the
terms of a gas purchase contract dated October 1, 1992, as amended (the "Gas
Purchase Contract"). The Gas Purchase Contract provides for a pricing mechanism
during an initial five-year period, which expired on December 31, 1997, and
continuing for one or more consecutive additional one-year terms unless and
until WPX Gas Resources exercises it annual option, exercisable fifteen days
prior to the end of each contract year, to discontinue purchasing gas under the
pricing mechanism of the Gas Purchase Contract and instead purchase gas at a
monthly market based price. WPX Gas Resources has not exercised this option and
therefore the pricing mechanism will continue to remain in effect through at
least December 31, 2001.

         Under the pricing mechanism of the Gas Purchase Contract, when the
market price is less than $1.70 per MMBtu (the "Minimum Purchase Price"), the
Trust will be paid the Minimum Purchase Price for the gas and an account (the
"Price Credit Account") will be maintained to identify the accrued and
unrecouped amount of payments made to the Trust in excess of the market price.
Any amounts in the Price Credit Account are subject to future recoupent when the
market price exceeds the Minimum Purchase Price. As of March 31, 2001, there
were no remaining unrecouped price credits in the Price Credit Account. To the
extent there may in the future be a balance in the Price Credit account, the
entitlement to recoup price credits means that if and when the index price is
above the Minimum Purchase Price, future royalty income paid to the Trust would
be reduced until such time as such Price Credit Account is once again reduced to
zero. Corresponding cash distributions to Unitholders would also be reduced.

         While the terms of the Gas Purchase Agreement pricing mechanism remain
in place and no balance exists in the Price Credit Account, when the market
price for natural gas exceeds $1.94 price per MMBtu (as was the case during the
first quarter of 2001), the Trust receives only 50 percent of the excess of the
market price over the $1.94 price per MMBtu.

         The majority of the production attributable to the Trust is within
Federal units. Unit participating areas are formed by pooling production from
the participating area. Entitlement to the pooled production is based on each
party's acreage in the participating area divided by the total participating
acreage. Wells drilled outside the participating area may create an enlargement
to the participating area and a revision of the Unit ownership entitlement. The
Bureau of Land Management ("BLM") must approve Unit participating area
expansions. The effective date for Unit expansions is retroactive to the date
the well creating the expansion was tested. The revenues presented in the
accompanying statements of distributable income are on an entitlement basis and
reflect the most recent BLM participating area approvals at March 31, 2001 and
2000, respectively. There are pending or anticipated applications or approvals
for additional participating area enlargements. WPC has advised the Trustee that
it does not believe that final approval of these Unit participating area
enlargements and the resulting retroactive adjustments, if any, will have a
material impact on the revenues as presented in these statements.


                                       11
<PAGE>   12
         The Trustee has been advised by WPC that the Minerals Management
Service ("MMS"), a subagency of the U.S. Department of the Interior, has from
time to time considered the inclusion of the value of the Section 29 tax credits
attributable to coal seam gas production in the calculation of gross proceeds
for purposes of calculating the royalty that is payable to the MMS. On August
30, 1993, the U.S. Office of the Inspector General (the "OIG") issued an audit
report stating that Section 29 tax credits should be included in the calculation
of gross proceeds and recommending that the MMS pursue collection of additional
royalties with respect to past and future production. On December 8, 1993,
however, the Office of the Solicitor of the U.S. Department of the Interior gave
its opinion to the MMS that the report of the OIG was incorrect and that Section
29 tax credits are not part of gross proceeds for the purpose of Federal royalty
calculations. WPC believes that any such inclusion of the value of Section 29
tax credits for the purposes of calculating royalty payments required to be made
on Federal and Indian lands would be inappropriate since all mineral interest
owners, including royalty owners, are entitled to Section 29 tax credits for
their proportionate share of qualifying coal seam gas production. WPC has
advised the Trustee that it would vigorously oppose any attempt by the MMS to
require the inclusion of the value of Section 29 tax credits in the calculation
of gross proceeds. However, if such regulations were adopted and upheld, royalty
payments would be increased which would decrease NPI Net Proceeds and,
therefore, the amounts payable to the Trust. The reduction in amounts payable to
the Trust would cause a corresponding reduction in associated Section 29 tax
credits available to Unitholders.

         On January 5, 2001, the State of New Mexico, acting under authority of
the MMS, presented WPC with an Audit Issue Letter for the alleged underpayment
of royalties in the amount of $948,501, on gas produced from the Underlying
Properties due to federal royalty owners during the time period from January
1992 through December 1996. MMS regulations permit a lessee to deduct from its
gross proceeds its reasonable actual costs of transportation and processing to
transport the gas form the lease to the point of sale in calculating the market
value of its production. The State of New Mexico claims that certain costs of
removing and transporting carbon dioxide gas are not deductible. On March 22,
2001, WPC responded to the Audit Issue Letter and contested the State of New
Mexico's claim for additional royalties as being contrary to law. While WPC
believes that its past computations have been appropriately stated, applying the
MMS methodology asserted by the State of New Mexico could potentially result in
negative adjustments to amounts previously paid to the Trust of approximately
$3,000,000.

7.       NPI PERCENTAGE REDUCTION

         From the Trust's inception until the fourth quarter of 2000, the NPI
generally entitled the Trust to receive 81 percent of the NPI Net Proceeds.
However, under the terms of the Conveyance, at the point that cumulative
production from the Underlying Properties has exceeded 178.5 Bcf of gas and the
internal rate of return of the "after tax cash flow per Trust Unit" (as defined
in the Conveyance) is equal to or greater than 12 percent, the percentage of NPI
Net Proceeds payable in respect of the NPI is automatically and permanently
reduced to 60 percent. The NPI percentage is not subject to further reduction or
other adjustment regardless of the future amount of cumulative production or the
achieved internal rate of return. These criteria for reduction of the NPI
percentage were reached or exceeded during the fourth quarter of 2000, and
consequently, the percentage of NPI Net Proceeds the Trust is entitled to
receive under the NPI has since such time been permanently reduced from 81


                                       12
<PAGE>   13
percent to 60 percent, and Quatro Finale's retained percentage of NPI Net
Proceeds has been correspondingly increased from 19 percent to 40 percent.

         It is expected that the reduction in the NPI percentage will
substantially reduce the distributions paid to the Trust, and in turn the
Quarterly Distribution Amounts payable to the Unitholders, beginning with the
Quarterly Distribution Amount for the first Quarter of 2001, which generally
related to the proceeds from production occurring during the fourth quarter of
2000.

Item 2.  Trustee's Discussion and Analysis of Financial Condition and Results
         of Operations.

         The Trust makes quarterly cash distributions to holders of units of
beneficial interest ("Units") in the Trust ("Unitholders"). The only assets of
the Trust, other than cash and cash equivalents being held for the payment of
expenses and liabilities and for distribution to Unitholders, are net profits
interests (the "Royalty Interests") in certain proved coal seam gas properties
located in the San Juan Basin of New Mexico and Colorado (the "Underlying
Properties"). The Royalty Interests owned by the Trust burden the Underlying
Properties, which are owned by Quatro Finale LLC and not the Trust.

         Distributable income of the Trust consists of the excess of royalty
income plus interest income over the general and administrative expenses of the
Trust. Upon receipt by the Trust, royalty income is invested in short-term
investments in accordance with the Trust Agreement (as defined in Note 1 to the
financial statements of the Trust appearing elsewhere in this Form 10-Q) until
its subsequent distribution to Unitholders.

         The amount of distributable income of the Trust for any quarter may
differ from the amount of cash available for distribution to Unitholders in such
quarter due to differences in the treatment of the expenses of the Trust in the
determination of those amounts. The financial statements of the Trust are
prepared on a modified cash basis pursuant to which the expenses of the Trust
are recognized when incurred. Consequently, the reported distributable income of
the Trust for any quarter is determined by deducting from the income received by
the Trust the amount of expenses incurred by the Trust during such quarter. The
amount of cash available for distribution to Unitholders, however, is determined
in accordance with the provisions of the Trust Agreement and reflects the
deduction from the income actually received by the Trust of the amount of
expenses actually paid by the Trust and adjustments for changes in reserves for
unpaid liabilities. See Note 4 to the financial statements of the Trust
appearing elsewhere in this Form 10-Q for additional information regarding the
determination of the amount of cash available for distribution to Unitholders.

Three Months Ended March 31, 2001 Compared to Three Months Ended March 31, 2000

         For the quarter ended March 31, 2001, royalty income received by the
Trust amounted to $5,818,139 as compared to $3,927,382 received for the same
quarter in 2000. The increase in royalty income is primarily due to higher
natural gas prices, partially offset by the reduction in the NPI percentage
payable to the Trust from 81% to 60%. Production related to the royalty income
received by the Trust in the first quarter of 2001 was 2,263,837 MMBtu at a 60%
NPI percentage to the Trust as compared to 3,577,711 MMBtu at an 81% NPI
percentage to the Trust for the same


                                       13
<PAGE>   14
quarter in 2000. Interest income for the quarter ended March 31, 2001 was
$21,734 compared to $15,327 for the same quarter in 2000. General and
administrative expenses during the first quarter of 2001 amounted to $212,969
compared to $204,428 for the same quarter in 2000.

         Distributable income for the quarter ended March 31, 2001 was
$5,626,904 or $.58 per Unit compared to $3,728,281 or $.39 per Unit for the
first quarter of 2000. This increase was the result of much higher natural gas
prices, partially offset by the reduction in the NPI percentage payable to the
Trust from 81% to 60%. A distribution of $.588028 per Unit was made on March 1,
2001 to Unitholders of record on February 14, 2001.

         Because the Trust incurs administrative expenses throughout a quarter
but receives its royalty income only once in a quarter, the Trustee established
in the first quarter of 1993 a cash reserve for the payment of expenses and
liabilities of the Trust. The Trustee thereafter has adjusted the amount of such
reserve in certain quarters as required for the payment of the Trust's expenses
and liabilities, in accordance with the provisions of the Trust Agreement. The
Trustee anticipates that it will maintain for the foreseeable future a cash
reserve which will fluctuate as expenses are paid and royalty income is
received.

         Royalty income to the Trust is attributable to the sale of depleting
assets. All of the Underlying Properties burdened by the Royalty Interests
consist of producing properties. Accordingly, the proved reserves attributable
to WPC's interest in the Underlying Properties are expected to decline
substantially during the term of the Trust and a portion of each cash
distribution made by the Trust will, therefore, be analogous to a return of
capital. Accordingly, cash yields attributable to the Units are expected to
decline over the term of the Trust.

         Royalty income received by the Trust in a given calendar quarter will
generally reflect the sum of (i) proceeds from the sale of gas produced from the
WI Properties during the preceding calendar quarter, plus (ii) cash received by
Quatro Finale with respect to the Farmout Properties either (a) during the
preceding calendar quarter or (b) if received in sufficient time to be paid to
the Trust, in the month immediately following such calendar quarter.
Accordingly, the royalty income included in distributable income for the quarter
ended March 31, 2001 was based on production volumes and natural gas prices for
the period October 2000 through December 2000, as shown in the table below. Due
to delays associated with the receipt of income related to the Farmout
Properties, the Trust's royalty income for the first quarter of 2001 reflects
estimated production volumes from the Farmout Properties for the months of
September 2000 through November 2000, as shown in the table below. The
production volumes included in the table below are for production attributable
to the Underlying Properties, and not for production attributable to the Trust's
Royalty Interests and are net of the amount of production attributable to Quatro
Finale's royalty obligations to third parties, which is determined by
contractual arrangement with such parties.


                                       14
<PAGE>   15
<TABLE>
<CAPTION>
                                          Three Months          Three Months
                                             Ended                  Ended
                                       December 31, 2001      December 31, 2000
                                       -----------------      -----------------
<S>                                    <C>                    <C>
Production (MMBtu)(1)
     WI Properties                         3,011,243(2)            3,640,386(4)
     Farmout Properties                      761,819(3)              776,542(5)

Blanco Hub Spot Price
     ($/MMBtu)(6)                      $        4.98           $        2.43
Net Wellhead Price
     WI Properties ($/MMBtu)(6)        $        2.55           $         .98
</TABLE>

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

(1)      Million British Thermal Units.

(2)      Includes prior period adjustments of (218,422) MMBtu.

(3)      Reflects estimated volumes for September 2000 through November 2000.

(4)      Includes prior period adjustments of 67,046 MMBtu.

(5)      Reflects estimated volumes for September 1999 through November 1999.

(6)      Simple average of estimates for the months included in the period
         presented.


         Production from the WI Properties is generally sold by WPC to WPX Gas
Resources pursuant to the Gas Purchase Contract that provides certain
protections for Unitholders by providing that WPX Gas Resources will purchase
gas at a minimum purchase price of $1.70 even when the applicable index price
(which is equal to 97% of the Blanco Hub Spot Price) falls below $1.70 per
MMBtu, provided that WPX Gas Resources is entitled to accrue price credits in
the amount of any excess of the minimum price so paid over the applicable index
price. When the applicable index price exceeds $1.70 per MMBtu WPX Gas Resources
is entitled to recoup any price credits previously earned. The Gas Purchase
Contract protects and benefits WPX Gas Resources by only requiring it to pay 50%
of the difference between the applicable index price and $1.94 per MMBtu when
the applicable index price is greater than $1.94 per MMBtu. The Gas Purchase
Contract also provides that the price paid for gas by WPX Gas Resources is
reduced by the amount of gathering, processing and certain other costs paid by
WPX Gas Resources. See "Item 2 - The Royalty Interests - Gas Purchase Contract"
in the 2000 Annual Report for detailed information about the Gas Purchase
Contract and its impact on Trust income.

         The initial five-year term of the pricing provision ("Primary Term") of
the Gas Purchase Contract expired on December 31, 1997. Following the expiration
of the Primary Term, the pricing provision will continue in effect for one or
more consecutive additional one-year terms (each such term a "Contract Year")
unless and until WPX Gas Resources exercises its annual option, exercisable
fifteen days prior to the end of each Contract Year, to discontinue purchasing
gas from WPC under the pricing provision of the Gas Purchase Contract and
instead purchase gas at a monthly price equal to the index price of 97 percent
of the Blanco Hub Spot Price. WPX Gas Resources has not yet exercised this
option and the pricing mechanism of the Primary Term therefore has been and will
continue to remain in effect through at least December 31, 2001.

         The Blanco Hub Spot Price was above $2.00 per MMBtu during the first
quarter of 2001 and therefore the applicable index price under the Gas Purchase
Contract, which is equal to 97% of the


                                       15
<PAGE>   16
Blanco Hub Spot Price, was above $1.94 per MMBtu. In general, under the Gas
Purchase Contract, the Trust only receives the benefit of 50 percent of any
amount by which the applicable index price exceeds $1.94 per MMBtu.
Consequently, pursuant to the terms of the Gas Purchase Contract, WPX Gas
Resources paid Quatro Finale (as successor to WPC) an amount for gas purchased
equal to $1.94 per MMBtu, less the costs paid by WPX Gas Resources to gather and
process such gas and deliver it to specified delivery points plus 50 percent of
the excess of the applicable index price over $1.94 per MMBtu. The Blanco Hub
Spot Price remained above $2.00 per MMBtu in April 2001.

         The information in this Form 10-Q concerning production and prices
relating to the Underlying Properties is based on information prepared and
furnished by WPC to the Trustee. The Trustee has no control over and no
responsibility relating to the operation of the Underlying Properties.

Forward-Looking Statements

         This report on 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 fact included in this Form 10-Q, including,
without limitation, statements contained in this "Trustee's Discussion and
Analysis of Financial Condition and Results of Operations" regarding the Trust's
financial position and industry conditions, are forward-looking statements.
Although the Trustee believes that the expectations reflected in such
forward-looking statements are reasonable, it can give no assurance that such
expectations will prove to have been correct.

Item 3.  Quantitative and Qualitative Disclosures About Market Risk.

         The only assets of and sources of income to the Trust are the Royalty
Interests, which generally entitle the Trust to receive a share of the net
profits from natural gas production from the Underlying Properties.
Consequently, the Trust's financial results can be significantly affected by
fluctuations in natural gas prices and the Trust has commodity price risk
exposure associated with the natural gas markets in the United States. The
Royalty Interests do not entitle the Trust to control or influence the operation
of the Underlying Properties or the sale of gas produced therefrom. Natural gas
produced from the WI Properties, which comprises the majority of production
attributable to the Royalty Interests, is currently sold by Quatro Finale
pursuant to the terms of the Gas Purchase Contract. Although the Trust is not a
party to the Gas Purchase Contract, the Gas Purchase Contract may significantly
impact revenues to the Trust. Although the Gas Purchase Contract mitigates the
risk to the Trust of low gas prices, it also limits the ability of the Trust to
benefit from the effects of higher gas prices. See "Item 2 -- The Royalty
Interests -- Gas Purchase Contract" in the 2000 Annual Report for detailed
information about the Gas Purchase Contract and its impact on the Trust and
Unitholders.

         The Trust is a passive entity and other than the Trust's ability to
periodically borrow money as necessary to pay expenses, liabilities and
obligations of the Trust that cannot be paid out of cash held by the Trust, the
Trust is prohibited from engaging in borrowing transactions. The amount of any
such borrowings is unlikely to be material to the Trust. The Trust periodically
holds short term investments acquired with funds held by the Trust pending
distribution to Unitholders and funds held


                                       16
<PAGE>   17
in reserve for the payment of Trust expenses and liabilities. Because of the
short-term nature of these borrowings and investments and certain limitations
upon the types of such investments which may be held by the Trust, the Trustee
believes that the Trust is not subject to any material interest rate risk. The
Trust does not engage in transactions in foreign currencies which could expose
the Trust or Unitholders to any foreign currency related market risk.



                                       17
<PAGE>   18
                           PART II - OTHER INFORMATION

Items 1 through 5.

         Not applicable.

Item 6.  Exhibits and Reports on Form 8-K.

         (b)      No reports on Form 8-K were filed during the quarter for which
                  this report is filed.


                                       18
<PAGE>   19
                                   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.

                                 WILLIAMS COAL SEAM GAS ROYALTY TRUST

                                 By:  BANK OF AMERICA, N.A., Trustee



                                 By:         /s/ Ron Hooper
                                      ---------------------------------------
                                      Ron Hooper
                                      Senior Vice President and Administrator


               (The Trust has no directors or executive officers.)


Date:  May 14, 2001