EXHIBIT 99.1








February 23, 2011





XTO Energy Inc.


810 Houston Street, Suite 2000


Fort Worth, TX  76102


Re:
Underlying Properties (100%)

Relating to the Hugoton Royalty Trust

As of December 31, 2010 - SEC Pricing Case





Gentlemen:





At your request, Miller and Lents, Ltd. (MLL) estimated the proved reserves and future net revenues as of December 31, 2010, attributable to the XTO Energy Inc. (XTO) interest in certain oil and gas properties prior to inclusion in the Hugoton Royalty Trust, i.e., Underlying Properties (100%).  This report was prepared for XTO’s use for reserves and financial planning and was completed on January 7, 2011.  The properties consist of approximately 1,654 leases and 1,796 wells located primarily in Kansas, Oklahoma, and Wyoming.  The evaluated reserves include 100 percent of the reserves owned by XTO prior to inclusion in the Hugoton Royalty Trust, i.e., Underlying Properties
(100%).  The aggregate results of MLL’s evaluations are as follows:





Net Reserves


Future Net RevenuesReserves Category

Oil and

Condensate,

MBbls.


Gas,

MMcf


Undiscounted,

M$


Discounted at

10% Per Year,

M$KansasProved Developed Producing


198.0



22,196.9



71,069.8



41,055.8Proved Nonproducing


0.0



417.5



1,457.0



664.3Proved Undeveloped


0.0



1,169.8



2,101.1



746.4Subtotal


198.0



23,784.2



74,627.9



42,466.5OklahomaProved Developed Producing


2,224.8



178,392.5



646,584.1



345,151.8Proved Nonproducing


0.0



1,120.1



3,741.9



1,628.5Proved Undeveloped


335.9



26,016.9



66,378.6



14,548.2Subtotal


2,560.6



205,529.5



716,704.6



361,328.5WyomingProved Developed Producing


90.6



73,962.5



139,765.9



80,824.2Proved Undeveloped


11.7



11,717.9



14,190.6



-970.8Subtotal


102.3



85,680.3



153,956.5



79,853.4Total Underlying Properties (100%)Proved Developed Producing


2,513.4



274,551.8



857,419.8



467,031.8Proved Nonproducing


0.0



1,537.6



5,198.8



2,292.9Proved Undeveloped


347.6



38,904.6



82,670.3



14,323.7TOTAL


2,861.0



314,994.0



945,288.9



483,648.4




XTO Energy Inc.
February 23, 2011Page 2


MLL performed evaluations, which are designated as the SEC Pricing Case, using price and expense premises specified by XTO and described in detail on Attachment 1.





Proved reserves and future net revenues were estimated in accordance with the provisions contained in Securities and Exchange Commission Regulation S-X, Rule 4-10(a).  The Securities and Exchange Commission definition of proved reserves is shown on Attachment 2 (not included).  Gas volumes for each property are stated at the pressure and temperature bases appropriate for the sales contract or state regulatory authority; therefore, some of the aggregated totals may be stated at a mixed pressure base.  No provisions for the possible consequences, if any, of product sales imbalances were included in our projections since MLL received no relevant data.  Estimates of future net
revenues and discounted future net revenues are not intended and should not be interpreted to represent fair market values for the estimated reserves.  In MLL’s projections, future costs of abandoning facilities and wells were assumed to be offset by salvage values.  Estimated costs, if any, for restoration of producing properties to satisfy environmental standards are beyond the scope of this assignment.





Following Attachment 2 is a list of exhibits (not included) that include annual projections of future production and net revenues for each state and reserves category.  Also included in the exhibits are one-line summaries for the total royalty trust and for each state showing the proved reserves and future net revenues for the individual properties.  Projections of individual property future production and net revenues are included in separate volumes to this report.  These exhibits and volumes should not be relied upon independently of this narrative.





The proved developed producing reserves and production forecasts were estimated by production decline extrapolations, water-oil ratio trends, P/Z declines, or in a few cases, by volumetric calculations.  For some properties with insufficient performance history to establish trends, MLL estimated future production by analogy with other properties with similar characteristics.  The past performance trends of many properties were influenced by production curtailments, workovers, waterfloods, and/or infill drilling.  Actual future production may require that MLL’s estimated trends be significantly altered.





The estimated proved developed nonproducing reserves can be produced from existing well bores but require capital costs for recompletions or for pipeline connections.  These proved developed nonproducing reserves estimates were based on analogies with other wells that commercially produce from the same formation in the same field.  The timing of initial production was usually provided to us by XTO.  When actual production history is available for these nonproducing reserves, MLL’s reserves estimates may be significantly revised.





The estimated proved undeveloped reserves require significant capital expenditures, such as for planned drilling and completion costs.  The proved undeveloped reserves estimates for infill wells are based on analogies to similar infill wells in the same field and/or the production histories of offset wells in the same field.  As actual results of the planned drilling become available, MLL’s reserves estimates may be significantly revised.





Reserves estimates from volumetric calculations and from analogies are often less certain than reserves estimates based on well performance obtained over a period during which a substantial portion of the reserves was produced.





The data employed in MLL’s estimations of proved reserves and future net income were provided by XTO.  The current expenses for each lease were obtained from operating statements provided by XTO except for certain leases where XTO deducted items considered by XTO to be nonrecurring expenditures.  No overhead was included for those properties operated by XTO.  For some properties, such as large waterfloods, XTO assumed a decline in operating costs due to depleting production that was derived by forecasting a decrease in the property well count.  For some gas properties, XTO assumed operating costs would be split between a variable component and a fixed
component.  The variable component was a constant cost per thousand cubic feet of gas production and the fixed component was a constant cost per well completion.  None of the data provided to us by XTO, including, but not limited to, graphical representations and tabulations of past production performance, well tests and pressures, ownership interests, prices, and operating costs, were verified by us as such was not within the scope of MLL’s assignment.





XTO Energy Inc.
February 23, 2011Page 3


MLL considers the assumptions, data, methods and analytical procedures used in this report appropriate for the purpose hereof, and we have used all such methods and procedures that we consider necessary and appropriate to prepare the estimates of reserves herein.





The evaluations presented in this report, with the exceptions of those parameters specified by others, reflect MLL’s informed judgments and are subject to the inherent uncertainties associated with interpretation of geological, geophysical, and engineering information.  These uncertainties include, but are not limited to, (1) the utilization of analogous or indirect data and (2) the application of professional judgments.  Government policies and market conditions different from those employed in this study may cause (1) the total quantity of oil, natural gas liquids, or gas to be recovered, (2) actual production rates, (3) prices received, or (4) operating and capital costs to vary from
those presented in this report.  At this time, MLL is not aware of any regulations that would affect XTO’s ability to recover the estimated reserves.  Minor precision inconsistencies in subtotals may exist in the report due to truncation or rounding of aggregated values.





Miller and Lents, Ltd. is an independent oil and gas consulting firm.  No director, officer, or key employee of Miller and Lents, Ltd. has any financial ownership in XTO Energy Inc. or any related company.  MLL’s compensation for the required investigations and preparation of this report is not contingent on the results obtained and reported, and we have not performed other work that would affect MLL’s objectivity.  Preparation of this report was supervised by an officer of Miller and Lents, Ltd., who is a licensed Professional Engineer in the State of Texas and professionally qualified with more than 25 years of relevant experience in the estimation, assessment, and
evaluation of oil and gas reserves.





MLL’s work papers and data are in our files and available for review upon request.  If you have any questions regarding the above, or if MLL can be of further assistance, please call.


Yours very truly,



MILLER AND LENTS, LTD.

Texas Registered Engineering Firm No. F-1442By:
/S/ James C. PearsonJames C. Pearson, P. E.Chairman





JCP/slc








Attachment 1











12/31/10





Hugoton Royalty Trust (100%)





SEC PRICING CASE








A.
Oil Price
Average price during the 12-month period prior to 12/31/10 determined as the arithmetical average of the first-day-of-the-month price for each month during the year 2010.  The average price was $75.91 per barrel and was held constant through the life of the property.





B.
Gas/NGL Price
Average price during the 12-month period prior to 12/31/10 determined as the arithmetical average of the first-day-of-the-month price for each month during the year 2010.  The average price was $4.45 per Mcf and was held constant through the life of the property.





C.
Operating Costs
Current expenses held constant through the life of the property.  For some properties, expenses included a variable component that was a constant cost per unit of gas production and a fixed component that was a constant cost per well completion.


D.
Discount Rate
10% per year.