Exhibit
99.2





DeGolyer
and MacNaughton
  5001
Spring Valley Road
 Suite 800
East
 Dallas,
Texas 75244




February
9, 2010




Vanguard
Natural Resources


7700 San
Felipe


Suite
485


Houston,
Texas 77063




Gentlemen:




Pursuant
to your request, we have prepared estimates of the extent and value of the net
proved crude oil, condensate, natural gas liquids (NGL), and natural gas
reserves, as of December 31, 2009, of certain properties owned by Vanguard
Natural Resources (Vanguard). The properties appraised are located in the Gold
River North and Sun T S H fields in Texas. Vanguard has represented that these
properties account for 36 percent on a net equivalent barrel basis of Vanguard’s
net proved reserves as of December 31, 2009.





Estimates
of proved reserves presented in this report have been prepared in compliance
with the regulations promulgated by the United States Securities and Exchange
Commission (SEC). These reserves definitions are discussed in detail under the
Definition of Reserves heading of this letter.





Reserves
included herein are expressed as net reserves. Gross reserves are defined as the
total estimated petroleum to be produced from these properties after December
31, 2009. Net reserves are defined as that portion of the gross reserves
attributable to the interests owned by Vanguard after deducting all interests
owned by others. Gas quantities estimated herein are expressed as sales gas.
Sales gas is defined as that portion of the total gas to be delivered into a gas
pipeline for sale after separation, processing, fuel use, and flare. Gas
reserves are expressed at a temperature base of 60 degrees Fahrenheit (°F) and
at a pressure base of 14.65 pounds per square inch absolute (psia).
Condensate reserves estimated herein are those to be recovered by conventional
lease separation.





Values
shown herein are expressed in terms of future gross revenue, future net revenue,
and present worth. Future gross revenue is that revenue which will accrue to the
appraised interests from the production and sale of the estimated netreserves.
Future net revenue is calculated by deducting estimated production taxes, ad
valorem taxes, operating expenses, and capital costs from the future gross
revenue. Operating expenses include field operating expenses, transportation
expenses, compression charges, and an allocation of overhead that directly
relates to production activities. Future income tax expenses were not taken into
account in the preparation of these estimates. Present worth is defined as
future net revenue discounted at a specified arbitrary discount rate compounded
monthly over the expected period of realization.





Estimates
of oil, condensate, NGL, and natural gas should be regarded only as estimates
that may change as further production history and additional information become
available. Not only are such reserves estimates based on that information which
is currently available, but such estimates are also subject to the uncertainties
inherent in the application of judgmental factors in interpreting such
information.





Data used
in this audit were obtained from reviews with Vanguard personnel, Vanguard
files, from records on file with the appropriate regulatory agencies, and from
public sources. Additionally, this information includes data supplied by
Petroleum Information/Dwights LLC; Copyright 2009 Petroleum Information/Dwights
LLC. In the preparation of this report we have relied, without independent
verification, upon such information furnished by Vanguard with respect to
property interests, production from such properties, current costs of operation
and development, current prices for production, agreements relating to current
and future operations and sale of production, and various other information and
data that were accepted as represented. A field examination of the properties
was not considered necessary for the purposes of this report.








Methodology and
Procedures




Estimates
of reserves were prepared by the use of standard geological and engineering
methods generally accepted by the petroleum industry. The method or combination
of methods used in the analysis of each reservoir was tempered by experience
with similar reservoirs, stage of development, quality and completeness of basic
data, and production history.


When
applicable, the volumetric method was used to estimate the original oil in place
(OOIP) and the original gas in place (OGIP). Structure and isopach maps were
constructed to estimate reservoir volume. Electrical logs, radioactivity logs,
core analyses, and other available data were used to prepare these maps as well
as to estimate representative values for porosity and water saturation. When
adequate data were available and when circumstances justified, material balance
and other engineering methods were used to estimate OOIP or OGIP.





Estimates
of ultimate recovery were obtained after applying recovery factors to OOIP or
OGIP. These recovery factors were based on consideration of the type of energy
inherent in the reservoirs, analyses of the petroleum, the structural positions
of the properties, and the production histories. When applicable, material
balance and other engineering methods were used to estimate recovery factors. An
analysis of reservoir performance, including production rate, reservoir
pressure, and gas-oil ratio behavior, was used in the estimation of
reserves.





For
depletion-type reservoirs or those whose performance disclosed a reliable
decline in producing-rate trends or other diagnostic characteristics, reserves
were estimated by the application of appropriate decline curves or other
performance relationships. In the analyses of production-decline curves,
reserves were estimated only to the limits of economic production or to the
limit of the production licenses as appropriate.








Definition of
Reserves




Petroleum
reserves included in this report are classified as proved. Only proved reserves
have been evaluated for this report. Reserves classifications used in this
report are in accordance with the reserves definitions of Rules 4–10(a) (1)–(32)
of Regulation S–X of the SEC. Reserves are judged to be economically producible
in future years from known reservoirs under existing economic and operating
conditions and assuming continuation of current regulatory practices using
conventional production methods and equipment. In the analyses of
production-decline curves, reserves were estimated only to the limit of economic
rates of production under existing economic and operating conditions using
prices and costs consistent with the effective date of this report, including
consideration of changes in existing prices provided only by contractual
arrangements but not including escalations based upon future conditions. The
petroleum reserves are classified as follows:


Proved oil and gas reserves –
Proved oil and gas reserves are those quantities of oil and gas, which, by
analysis of geoscience and engineering data, can be estimated with reasonable
certainty to be economically producible—from a given date forward, from known
reservoirs, and under existing economic conditions, operating methods, and
government regulations—prior to the time at which contracts providing the right
to operate expire, unless evidence indicates that renewal is reasonably certain,
regardless of whether deterministic or probabilistic methods are used for the
estimation. The project to extract the hydrocarbons must have commenced or the
operator must be reasonably certain that it will commence the project within a
reasonable time.





(i) The
area of the reservoir considered as proved includes:


(A) The
area identified by drilling and limited by fluid contacts, if any, and (B)
Adjacent undrilled portions of the reservoir that can, with reasonable
certainty, be judged to be continuous with it and to contain economically
producible oil or gas on the basis of available geoscience and engineering
data.





(ii) In
the absence of data on fluid contacts, proved quantities in a reservoir are
limited by the lowest known hydrocarbons (LKH) as seen in a well penetration
unless geoscience, engineering, or performance data and reliable technology
establishes a lower contact with reasonable certainty.





(iii)
Where direct observation from well penetrations has defined a highest known oil
(HKO) elevation and the potential exists for an associated gas cap, proved oil
reserves may be assigned in the structurally higher portions of the reservoir
only if geoscience, engineering, or performance data and reliable technology
establish the higher contact with reasonable certainty.





(iv)
Reserves which can be produced economically through application of improved
recovery techniques (including, but not limited to, fluid injection) are
included in the proved classification when:


(A)
Successful testing by a pilot project in an area of the reservoir with
properties no more favorable than in the reservoir as a whole, the operation of
an installed program in the reservoir or an analogous reservoir, or other
evidence using reliable technology establishes the reasonable certainty of the
engineering analysis on which the project or program was based; and (B) The
project has been approved for development by all necessary parties and entities,
including governmental entities.





(v)
Existing economic conditions include prices and costs at which economic
producibility from a reservoir is to be determined. The price shall be the
average price during the 12-month period prior to the ending date of the period
covered by the report, determined as an unweighted arithmetic average of the
first-day-of-the-month price for each month within such period, unless prices
are defined by contractual arrangements, excluding escalations based upon future
conditions.





Developed oil and gas
reserves – Developed oil and gas reserves are reserves of any category
that can be expected to be recovered:





(i)
Through existing wells with existing equipment and operating methods or in which
the cost of the required equipment is relatively minor compared to the cost of a
new well; and





(ii)
Through installed extraction equipment and infrastructure operational at the
time of the reserves estimate if the extraction is by means not involving a
well.





Undeveloped reserves –Undeveloped oil and gas reserves are reserves of any category that are
expected to be recovered from new wells on undrilled acreage, or from existing
wells where a relatively major expenditure is required for
recompletion.





(i)
Reserves on undrilled acreage shall be limited to those directly offsetting
development spacing areas that are reasonably certain of production when
drilled, unless evidence using reliable technology exists that establishes
reasonable certainty of economic producibility at greater
distances.





(ii)
Undrilled locations can be classified as having undeveloped reserves only if a
development plan has been adopted indicating that they are scheduled to be
drilled within five years, unless the specific circumstances, justify a longer
time.


(iii)
Under no circumstances shall estimates for undeveloped reserves be attributable
to any acreage for which an application of fluid injection or other improved
recovery technique is contemplated, unless such techniques have been proved
effective by actual projects in the same reservoir or an analogous reservoir, as
defined in [section 210.4–10 (a) Definitions], or by other evidence using
reliable technology establishing reasonable certainty.








Primary Economic
Assumptions




The
following economic assumptions were used for estimating existing and future
prices and costs:




Oil,
Condensate, and NGL Prices




The oil,
condensate, and NGL prices were based on a 12-month average price (reference
price), calculated as the unweighted arithmetic average of the
first-day-of-the-month price for each month within the 12-month period prior to
the end of the reporting period, unless prices are defined by contractual
arrangements. Vanguard supplied differentials by field to a West Texas
Intermediate reference price of $61.04 per barrel and the prices were held
constant thereafter.




Natural
Gas Prices




The
natural gas prices were based on a reference price, calculated as the unweighted
arithmetic average of the first-day-of-the-month price for each month within the
12-month period prior to the end of the reporting period, unless prices are
defined by contractual arrangements. The gas prices were calculated for each
property using differentials furnished by Vanguard to the reference price of
$3.87 per thousand cubic feet and held constant thereafter.




Operating
and Capital Expenditures




Current
operating expenses provided by Vanguard were used in estimating future expenses
required to operate the properties. In certain cases, future expenses, either
higher or lower than current expenses, may have been used because of anticipated
changes in operating conditions. Initial operating expenses were held constant
for the lives of the properties. Vanguard currently delivers gas it produces in
South Texas to Enbridge Pipeline Texas Gathering (Enbridge) and into the
Enterprise Products Pipeline System for ultimate sale to Houston Pipeline
Company (HPL) and has provided data relating to the transportation expenses
necessary to do so. Gas from all future wells in any of the field areas also is
contracted to be delivered to either Enbridge or HPL.




Severance
Taxes




The Texas
Railroad Commission (TRRC) has certified certain producing formations in various
fields as tight gas sands. The main formations in these fields in this report
are the Olmos and the Escondido. Certain wells producing from these formations
will receive a reduction in severance taxes for a period of 10 years or until
such time as 50 percent of the drilling and completion costs are recovered. At
the end of that period, the severance tax rate reverts back to the standard
rate. The amount of severance tax reduction varies from well to well based on
the actual well cost and can typically range from 20 to 100 percent during this
recovery period. At the request of Vanguard, this severance tax reduction has
been appropriately considered for any existing wells that qualify, and for all
future wells that would likewise qualify.





While the
oil and gas industry may be subject to regulatory changes from time to time that
could affect an industry participant’s ability to recover its oil and gas
reserves, we are not aware of any such governmental actions which would restrict
the recovery of the December 31, 2009, estimated oil and gas volumes. The
reserves estimated in this report can be produced under current regulatory
guidelines.





The
estimated net proved reserves, as of December 31, 2009, of the properties
appraised are summarized as follows, expressed in thousands of barrels (Mbbl),
and millions of cubic feet (MMcf):





Net
      Proved ReservesOil
      and Condensate
              (Mbbl)
            
            
            NGL
              (Mbbl)
            
            
            Sales
      Gas
              (MMcf))Gold
      River NorthProved
      Developed Producing
            
            
            4
            
            
            
            423
            
            
            
            6,918Proved
      Developed Nonproducing
            
            
            0
            
            
            
            0
            
            
            
            0Proved
      Undeveloped
            
            
            18
            
            
            
            285
            
            
            
            4,672Total
      Proved Gold River North
            
            
            22
            
            
            
            708
            
            
            
            11,590Sun
      T S HProved
      Developed Producing
            
            
            87
            
            
            
            1,561
            
            
            
            12,251Proved
      Developed Nonproducing
            
            
            9
            
            
            
            129
            
            
            
            1,017Proved
      Undeveloped
            
            
            52
            
            
            
            821
            
            
            
            6,438Total
      Proved Sun T S H
            
            
            148
            
            
            
            2,511
            
            
            
            19,706Total
      Proved
            
            
            170
            
            
            
            3,219
            
            
            
            31,296





The
estimated future revenue attributable to Vanguard’s interests in the proved
reserves, as of December 31, 2009,of the
properties appraised is summarized as follows, expressed in thousands of dollars
(M$):





ProvedDeveloped
              Producing
            
            
            Developed
              Nonproducing
            
            
            Undeveloped
            
            
            TotalFuture
      Gross Revenue, M$
            
            
            139,460
            
            
            
            8,920
            
            
            
            79,575
            
            
            
            227,955Production
      and Ad Valorem Taxes, M$
            
            
            12,598
            
            
            
            869
            
            
            
            6,798
            
            
            
            20,265Operating
      Expenses, M$
            
            
            45,170
            
            
            
            1,528
            
            
            
            15,475
            
            
            
            62,173Capital
      Costs, M$
            
            
            0
            
            
            
            1,350
            
            
            
            23,864
            
            
            
            25,214Future
      Net Revenue*, M$
            
            
            81,692
            
            
            
            5,173
            
            
            
            33,438
            
            
            
            120,303Present
      Worth at 10 Percent*, M$
            
            
            42,995
            
            
            
            2,055
            
            
            
            7,372
            
            
            
            52,422*
      Future income tax expenses were not taken into account in the preparation
      of these estimates.





In our
opinion, the information relating to estimated proved reserves, estimated future
net revenue from proved reserves, and present worth of estimated future net
revenue from proved reserves of oil, condensate, natural gas liquids, and gas
contained in this report has been prepared in accordance with Paragraphs
932-235-50-4, 932-235-50-6, 932-235-50-7, 932-235-50-9, 932-235-50-30, and
932-235-50-31(a), (b), and (e) of the Accounting Standards Update 932-235-50,
Extractive Industries – Oil
and Gas (Topic 932): Oil and Gas Reserve Estimation and Disclosures
(January 2010) of the Financial Accounting Standards Board and Rules 4–10(a)
(1)–(32) of Regulation S–X and Rules 302(b), 1201, 1202(a) (1), (2), (3), (4),
(8), and 1203(a) of Regulation S–K of the Securities and Exchange Commission;
provided, however, future income tax expenses have not been taken into account
in estimating the future net revenue and present worth values set forth
herein.








DeGolyer
and MacNaughton is an independent petroleum engineering consulting firm that has
been providing petroleum consulting services throughout the world for over 70
years. DeGolyer and MacNaughton does not have any financial interest, including
stock ownership, in Vanguard. Our fees were not contingent on the results of our
evaluation. This letter report has been prepared at the request of Vanguard and
should not be used for purposes other than those for which it is intended.
DeGolyer and MacNaughton has used all procedures and methods that it considers
necessary to prepare this report.




Submitted,









/s/
DeGolyer and MacNaughton


DeGOLYER
and MacNAUGHTONTexas Registered
Engineering Firm F-716




CERTIFICATE of
QUALIFICATION




I, Paul
J. Szatkowski, Petroleum Engineer with DeGolyer and MacNaughton, 5001 Spring
Valley Road, Suite 800 East, Dallas, Texas, 75244 U.S.A., hereby
certify:





1.
            That
      I am a Senior Vice President with DeGolyer and MacNaughton, which company
      did prepare the letter report addressed to Vanguard dated February 9,
      2010, and that I, as Senior Vice President, was responsible for the
      preparation of this report.





2.
            That
      I attended Texas A&M University, and that I graduated with a Bachelor
      of Science degree in Petroleum Engineering in the year 1974; that I am a
      Registered Professional Engineer in the State of Texas; that I am a member
      of the International Society of Petroleum Engineers and the American
      Association of Petroleum Geologists; and that I have in excess of
      35 years of experience in the oil and gas reservoir studies and
      reserves evaluations.