Exhibit 99.1

GRAPHIC WORLDWIDE PETROLEUM CONSULTANTSENGINEERING  GEOLOGY  GEOPHYSICS  PETROPHYSICS

CHAIRMAN & CEOC.H. (SCOTT) REES III PRESIDENT & COODANNY D. SIMMONS EXECUTIVE
VPG. LANCE BINDER

EXECUTIVE COMMITTEEP. SCOTT FROST - DALLAS
J. CARTER HENSON, JR. - HOUSTON
DAN PAUL SMITH - DALLAS
JOSEPH J. SPELLMAN - DALLAS
THOMAS J. TELLA II - DALLAS


February 11,
2010

Mr. Lynn
A. Peterson
Kodiak Oil & Gas Corp.
1625 Broadway, Suite 250
Denver, Colorado 80202

Dear
Mr. Peterson:

In
accordance with your request, we have estimated the proved reserves and future revenue, as of December 31, 2009, to the Kodiak Oil & Gas Corp. (Kodiak) interest in
certain oil and gas properties located in Montana, North Dakota, and Wyoming. It is our understanding that the proved reserves estimated in this report constitute all of the proved reserves owned by
Kodiak. The estimates in this report have been prepared in accordance with the definitions and guidelines of the U.S. Securities and Exchange Commission (SEC) and, with the exception of the exclusion
of future income taxes, conform to the FASB Accounting Standards Codification Topic 932, Extractive ActivitiesOil and Gas. Definitions are presented immediately following this letter.
This report has been prepared for Kodiak's use in filing with the SEC.

We
estimate the net reserves and future net revenue to the Kodiak interest in these properties, as of December 31, 2009, to be:

Net Reserves

Future Net Revenue ($)Category

Oil
(Barrels)

Gas
(MCF)

Total

Present Worth
at 10%Proved Developed Producing


1,170,435


1,454,904


45,758,400


25,842,400Proved Undeveloped


2,646,309


2,393,574


63,370,700


13,220,400Total Proved


3,816,744


3,848,478


109,129,100


39,062,800


The
oil reserves shown include crude oil and condensate. Oil volumes are expressed in barrels that are equivalent to 42 United States gallons. Gas volumes are expressed in thousands of
cubic feet (MCF) at standard temperature and pressure bases.

The
estimates shown in this report are for proved developed producing and proved undeveloped reserves. Our study indicates that there are no proved developed non-producing
reserves for these properties at this time. As requested, probable and possible reserves that exist for these properties have not been included. This report does not include any value that could be
attributed to interests in undeveloped acreage beyond those tracts for which undeveloped reserves have been
estimated. Reserves categorization conveys the relative degree of certainty; reserves subcategorization is based on development and production status. The estimates of reserves and future revenue
included herein have not been adjusted for risk.

Future
gross revenue to the Kodiak interest is prior to deducting state production taxes and ad valorem taxes. Future net revenue is after deductions for these taxes, future capital
costs, and operating expenses but before consideration of federal income taxes. The future net revenue has been discounted at an annual rate of 10 percent to determine its present worth. The
present worth is shown to indicate the effect of time on the value of money and should not be construed as being the fair market value of the properties.

4500 THANKSGIVING TOWER  1601 ELM STREET  DALLAS, TEXAS 75201-4754  PH: 214-969-5401  FAX: 214-969-5411

nsai@nsai-petro.com1221 LAMAR STREET, SUITE 1200  HOUSTON, TEXAS 77010-3072  PH: 713-654-4950  FAX: 713-654-4951

netherlandsewell.com


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GRAPHIC

For
the purposes of this report, we did not perform any field inspection of the properties, nor did we examine the mechanical operation or condition of the wells and facilities. We have
not investigated possible environmental liability related to the properties; therefore, our estimates do not include any costs due to such possible liability. Also, our estimates do not include any
salvage value for the lease and well equipment or the cost of abandoning the properties.

Prices
used in this report are based on the 12-month unweighted arithmetic average of the first-day-of-the-month price for the
period January through December 2009. For oil volumes, the average regional posted prices are adjusted by field for quality, transportation fees, and local price differentials. For gas volumes, the
average regional spot prices are adjusted by field for energy content, transportation fees, and local price differentials. When applicable, gas prices have been adjusted to include the value for
natural gas liquids. As a reference, for the same time period the average Plains Marketing, L.P. West Texas Intermediate posted price was $57.65 per barrel and the average Platts Gas DailyHenry
Hub spot price was $3.866 per MMBTU. All prices are held constant throughout the lives of the properties.

Lease
and well operating costs used in this report are based on operating expense records of Kodiak. These costs include the per-well overhead expenses allowed under joint
operating agreements along with estimates of costs to be incurred at and below the district and field levels. Headquarters general and administrative overhead expenses of Kodiak are included to the
extent that they are covered under joint operating agreements for the operated properties. Lease and well operating costs are held constant throughout the lives of the properties. Capital costs are
included as required for workovers, new development wells, and production equipment. The future capital costs are held constant to the date of expenditure.

We
have made no investigation of potential gas volume and value imbalances resulting from overdelivery or underdelivery to the Kodiak interest. Therefore, our estimates of reserves and
future revenue do not include adjustments for the settlement of any such imbalances; our projections are based on Kodiak receiving its net revenue interest share of estimated future gross gas
production.

The
reserves shown in this report are estimates only and should not be construed as exact quantities. Proved reserves are those quantities of oil and gas which, by analysis of
engineering and geoscience data, can be estimated with reasonable certainty to be economically producible. If the reserves are recovered, the revenues therefrom and the costs related thereto could be
more or less than the estimated amounts. Because of governmental policies and uncertainties of supply and demand, the sales rates, prices received for the reserves, and costs incurred in recovering
such reserves may vary from assumptions made while preparing this report. Estimates of reserves may increase or decrease as a result of future operations, market conditions, or changes in regulations.

For
the purposes of this report, we used technical and economic data including, but not limited to, well logs, geologic maps, well test data, production data, historical price and cost
information, and property ownership interests. The reserves in this report have been estimated using deterministic methods; these estimates have been prepared in accordance with generally accepted
petroleum engineering and evaluation principles. We used standard engineering and geoscience methods, or a combination of methods, such as performance analysis, volumetric analysis, and analogy, that
we considered to be appropriate and necessary to establish reserves quantities and reserves categorization that conform to SEC definitions and guidelines. A substantial portion of these reserves are
for undeveloped locations and therefore are based on estimates of reservoir volumes and recovery efficiencies along with analogy to properties with similar geologic and reservoir characteristics. In
evaluating the information at our disposal concerning this report, we have excluded from our consideration all matters as to which the controlling interpretation may be legal or accounting, rather
than engineering and geoscience. As in all aspects of oil and gas evaluation, there are uncertainties inherent in the interpretation of engineering and geoscience data; therefore, our conclusions
necessarily represent only informed professional judgment.

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GRAPHIC

The
titles to the properties have not been examined by Netherland, Sewell & Associates, Inc. (NSAI), nor has the actual degree or type of interest owned been independently
confirmed. The data used in our estimates were obtained from Kodiak, public data sources, and the nonconfidential files of NSAI and were accepted as accurate. Supporting geoscience, field performance,
and work data are on file in our office. The technical persons responsible for preparing the reserves estimates presented herein meet the requirements regarding qualifications, independence,
objectivity, and confidentiality set forth in the Standards Pertaining to the Estimating and Auditing of Oil and Gas Reserves Information promulgated by the Society of Petroleum Engineers. We are
independent petroleum engineers, geologists, geophysicists, and petrophysicists; we do not own an interest in these properties and are not employed on a contingent basis.

Sincerely,NETHERLAND, SEWELL & ASSOCIATES, INC.Texas Registered Engineering Firm F-002699By:

/s/ C. H. (SCOTT) REES III C. H. (Scott) Rees III, P. E. Chairman and Chief Executive OfficerBy:

/s/ DAN PAUL SMITH Dan Paul Smith, P.E. 49093 Senior Vice President

By:

/s/ JOHN G. HATTNER John G. Hattner, P.G. 559 Senior Vice PresidentDate Signed: February 11, 2010

Date Signed: February 11, 2010DPS: AHA


Please
be advised that the digital document you are viewing is provided by Netherland, Sewell & Associates, Inc. (NSAI) as a convenience to our clients. The digital document is intended to be
substantively the same as the original signed document maintained by NSAI. The digital document is subject to the parameters, limitations, and conditions stated in the original document. In the event
of any differences between the digital document and the original document, the original document shall control and supersede the digital document.

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DEFINITIONS OF OIL AND GAS RESERVESAdapted from U. S. Securities and Exchange Commission Regulation S-X Section 210.4-10(a)

The
following definitions are set forth in U.S. Securities and Exchange Commission (SEC) Regulation S-X Section 210.4-10
(a). Also included is supplemental information from (1) the 2007 Petroleum Resources Management System approved by the Society of Petroleum Engineers, (2) the FASB Accounting Standards
Codification Topic 932, Extractive ActivitiesOil and Gas, and (3) the SEC's Compliance and Disclosure Interpretations.

(1)Acquisition of properties.Costs incurred to purchase, lease or otherwise acquire a property, including
costs of lease bonuses and options to purchase or lease properties, the portion of costs applicable to minerals when land including mineral rights is purchased in fee, brokers' fees, recording fees,
legal costs, and other costs incurred in acquiring properties.

(2)Analogous reservoir.Analogous reservoirs, as used in resources assessments, have similar rock and fluid
properties, reservoir conditions (depth, temperature, and pressure) and drive mechanisms, but are typically at a more advanced stage of development than the reservoir of interest and thus may provide
concepts to assist in the interpretation of more limited data and estimation of recovery. When used to support proved reserves, an "analogous reservoir" refers to a reservoir that shares the following
characteristics with the reservoir of interest:



Instruction to paragraph (a)(2):    Reservoir properties must, in the aggregate, be no more favorable in the analog than in the
reservoir of interest.

(3)Bitumen.Bitumen, sometimes referred to as natural bitumen, is petroleum in a solid or
semi-solid state in natural deposits with a viscosity greater than 10,000 centipoise measured at original temperature in the deposit and atmospheric pressure, on a gas free basis. In its
natural state it usually contains sulfur, metals, and other non-hydrocarbons.

(4)Condensate.Condensate is a mixture of hydrocarbons that exists in the gaseous phase at original reservoir
temperature and pressure, but that, when produced, is in the liquid phase at surface pressure and temperature.

(5)Deterministic estimate.The method of estimating reserves or resources is called deterministic when a single
value for each parameter (from the geoscience, engineering, or economic data) in the reserves calculation is used in the reserves estimation procedure.

(6)Developed oil and gas reserves.Developed oil and gas reserves are reserves of any category that can be
expected to be recovered:



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(7)Development costs.Costs incurred to obtain access to proved reserves and to provide facilities for
extracting, treating, gathering and storing the oil and gas. More specifically, development costs, including depreciation and applicable operating costs of support equipment and facilities and other
costs of development activities, are costs incurred to:



(8)Development project.A development project is the means by which petroleum resources are brought to the
status of economically producible. As examples, the development of a single reservoir or field, an incremental development in a producing field, or the integrated development of a group of several
fields and associated facilities with a common ownership may constitute a development project.

(9)Development well.A well drilled within the proved area of an oil or gas reservoir to the depth of a
stratigraphic horizon known to be productive.

(10)Economically producible.The term economically producible, as it relates to a resource, means a resource
which generates revenue that exceeds, or is reasonably expected to exceed, the costs of the operation. The value of the products that generate revenue shall be determined at the terminal point of oil
and gas producing activities as defined in paragraph (a)(16) of this section.

(11)Estimated ultimate recovery (EUR).Estimated ultimate recovery is the sum of reserves remaining as of a
given date and cumulative production as of that date.

(12)Exploration costs.Costs incurred in identifying areas that may warrant examination and in examining
specific areas that are considered to have prospects of containing oil and gas reserves, including costs of drilling exploratory wells and exploratory-type stratigraphic test wells.
Exploration costs may be incurred both before acquiring the related property (sometimes referred to in part as prospecting costs) and after acquiring the property. Principal types of exploration
costs, which include

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depreciation
and applicable operating costs of support equipment and facilities and other costs of exploration activities, are:



(13)Exploratory well.An exploratory well is a well drilled to find a new field or to find a new reservoir in a
field previously found to be productive of oil or gas in another reservoir. Generally, an exploratory well is any well that is not a development well, an extension well, a service well, or a
stratigraphic test well as those items are defined in this section.

(14)Extension well.An extension well is a well drilled to extend the limits of a known reservoir.

(15)Field.An area consisting of a single reservoir or multiple reservoirs all grouped on or related to the
same individual geological structural feature and/or stratigraphic condition. There may be two or more reservoirs in a field which are separated vertically by intervening impervious strata, or
laterally by local geologic barriers, or by both. Reservoirs that are associated by being in overlapping or adjacent fields may be treated as a single or common operational field. The geological terms
"structural feature" and "stratigraphic condition" are intended to identify localized geological features as opposed to the broader terms of basins, trends, provinces, plays,
areas-of-interest, etc.

(16)Oil and gas producing activities.



Instruction 1 to paragraph (a)(16)(i):    The oil and gas production function shall be regarded as ending at a "terminal point",
which is the outlet valve on the lease or field storage tank. If unusual physical or

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operational
circumstances exist, it may be appropriate to regard the terminal point for the production function as:

Instruction 2 to paragraph (a)(16)(i):    For purposes of this paragraph (a)(16), the term saleable hydrocarbonsmeans
hydrocarbons that are saleable in the state in which the hydrocarbons are delivered.



(17)Possible reserves.Possible reserves are those additional reserves that are less certain to be recovered
than probable reserves.



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(18)Probable reserves.Probable reserves are those additional reserves that are less certain to be recovered
than proved reserves but which, together with proved reserves, are as likely as not to be recovered.



(19)Probabilistic estimate.The method of estimation of reserves or resources is called probabilistic when the
full range of values that could reasonably occur for each unknown parameter (from the geoscience and engineering data) is used to generate a full range of possible outcomes and their associated
probabilities of occurrence.

(20)Production costs.



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(21)Proved area.The part of a property to which proved reserves have been specifically attributed.

(22)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.



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(23)Proved properties.Properties with proved reserves.

(24)Reasonable certainty.If deterministic methods are used, reasonable certainty means a high degree of
confidence that the quantities will be recovered. If probabilistic methods are used, there should be at least a 90% probability that the quantities actually recovered will equal or exceed the
estimate. A high degree of confidence exists if the quantity is much more likely to be achieved than not, and, as changes due to increased availability of geoscience (geological, geophysical, and
geochemical), engineering, and economic data are made to estimated ultimate recovery (EUR) with time, reasonably certain EUR is much more likely to increase or remain constant than to decrease.

(25)Reliable technology.Reliable technology is a grouping of one or more technologies (including computational
methods) that has been field tested and has been demonstrated to provide reasonably certain results with consistency and repeatability in the formation being evaluated or in an analogous formation.

(26)Reserves.Reserves are estimated remaining quantities of oil and gas and related substances anticipated to
be economically producible, as of a given date, by application of development projects to known accumulations. In addition, there must exist, or there must be a reasonable expectation that there will
exist, the legal right to produce or a revenue interest in the production, installed means of delivering oil and gas or related substances to market. and all permits and financing required to
implement the project.

Note to paragraph (a)(26):    Reserves should not be assigned to adjacent reservoirs isolated by major, potentially sealing, faults
until those reservoirs are penetrated and evaluated as economically producible. Reserves should not be assigned to areas that are clearly separated from a known accumulation by a
non-productive reservoir (i.e., absence of reservoir, structurally low reservoir, or negative test results). Such areas may contain prospective resources (i.e., potentially
recoverable resources from undiscovered accumulations).





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(27)Reservoir.A porous and permeable underground formation containing a natural accumulation of producible oil
and/or gas that is confined by impermeable rock or water barriers and is individual and separate from other reservoirs.

(28)Resources.Resources are quantities of oil and gas estimated to exist in naturally occurring accumulations.
A portion of the resources may be estimated to be recoverable, and another portion may be considered to be unrecoverable. Resources include both discovered and undiscovered accumulations.

(29)Service well.A well drilled or completed for the purpose of supporting production in an existing field.
Specific purposes of service wells include gas injection, water injection, steam injection, air injection. salt-water disposal, water supply for injection, observation, or injection for
in-situ combustion.

(30)Stratigraphic test well.A stratigraphic test well is a drilling effort, geologically directed, to obtain
information pertaining to a specific geologic condition. Such wells customarily are drilled without the intent of being completed for hydrocarbon production. The classification also includes tests
identified as core tests and all types of expendable holes related to hydrocarbon exploration. Stratigraphic tests are classified as "exploratory type" if not drilled in a known area or "development
type" if drilled in a known area.

(31)Undeveloped oil and gas 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.





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(32)Unproved properties.Properties with no proved reserves.

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