Section 1 

Introduction 

1.0 INTRODUCTION 

As the energy needs of the Nation continue to grow, the sedimentary basins in the Interior West 

have been identified as a significant future supply source to help meet these needs, especially for 

natural gas. The United States currently uses about 23 trillion cubic feet (Tcf) of natural gas 

annually. The U.S. produces approximately 19 Tcf of its annual natural gas demand and imports 

the remaining 4 Tcf. The EIA of the DOE in its Energy Outlook 2003 reference case projects that 

the demand for natural gas will rise to just under 35 Tcf by 2025. The Minerals Management 

Service (MMS) estimated in 2000 that approximately 58 percent of our country’s undiscovered 

natural gas resources (over 362 Tcf) lie under the Outer Continental Shelf. However, production 

in the shallow water areas of the Gulf of Mexico has been steadily declining – some 13 percent 

from 1997 through 1999. The study presented here estimates that there are 138 Tcf of natural gas 

resources and reserves on Federal lands in the Interior West, making it the second largest natural 

gas resource in the United States after the Outer Continental Shelf. This 138 Tcf is sufficient to 

heat all of the 55 million homes that use natural gas in the United States for 39 years. 

At the same time, the Interior West is one where multiple use interests and attendant 

environmental issues often intersect. Multiple uses of the Federal lands in this region, which 

include but are not limited to grazing, forestry, recreation, wildlife habitat, open space, 

wilderness, rights-of-way, and minerals exploration and production often conflict with each other. 

The population of the region is growing rapidly, and approximately 22 million people live within 

25 miles of Federal lands. Recognizing this situation, Congress directed that quantitative 

assessments of the Nation’s Federal onshore oil and gas resources be analyzed in relation to 

Federal actions that inhibit access to these resources in order to add clarity to the debate and assist 

energy policymakers and Federal land managers in making decisions concerning oil and gas 

resource development. 

The studies reported here were conducted to address these needs for a part of the Interior West 

(figure 1a), comprising the Paradox/San Juan, Uinta/Piceance, Greater Green River, and Powder 

River basins and the Montana Thrust Belt. About 59 million acres of Federal lands (including 

split estate) present among the almost 104 million acres in these study areas, were analyzed. 

A full set of acronyms used in this report, as well as a glossary, can be found in Appendices 1 and 

2, respectively. 

1.1 BACKGROUND 

Access to Federal lands is probably the most oft-cited issue affecting oil and gas production in the 

Interior West. The restrictions and leasing stipulations that constrain access to Federal lands in 

the region are a complicated patchwork of requirements that increase costs and delay activity. 

They range from areas unavailable for leasing, to areas where the minerals can be leased but the 

surface of the land may not be occupied in order to recover those resources. There are also 

limitations on drilling activities due to a variety of environmental considerations. 

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Section 1 

Introduction 

Recent attempts to understand the impacts of Federal land management decisions on access to oil 

and gas resources began with a 1999 National Petroleum Council (NPC) study. In its report1 

on 

natural gas, the NPC (an advisory committee to the Secretary of Energy) forecast that U.S. 

demand for natural gas would grow to 29 Tcf in 2010 and would exceed 31 Tcf in 2015. 

One of the objectives of the NPC study was to collect and analyze data on land use and natural 

gas resources for Federal lands in the Interior West to identify opportunities for increasing natural 

gas supply from this area. The NPC identified the Interior West as a significant future source of 

gas supply to help meet the anticipated growing demand. However, the NPC also estimated that 

about 40 percent (137 Tcf) of the potential supply from this region is currently unavailable for 

leasing or is subject to surface-use access restrictions because of competing uses or 

environmental considerations. This analysis was based on a limited sample of Federal lands in the 

region. The NPC report was the first assessment of access constraints associated with Federal 

land use designations and related environmental stipulations in the Interior West. The report was 

developed through a cooperative effort of Federal agencies, including the DOE, the BLM, and the 

U.S. Department of Agriculture-Forest Service (USDA-FS) and industry. Representatives from 

State and local governments and other stakeholders also participated. 

1 Meeting the Challenges of the Nation’s Growing Natural Gas Demand, December 1999, available on the 

NPC website: http://www.npc.org/reports/ng.html. 

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Introduction

Figure 1a Outline of Study Areas Showing Federal Lands 

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Section 1 

Introduction 

In response to the NPC recommendation, DOE, with the cooperation of the Department of the 

Interior (DOI) and the U.S. Department of Agriculture (USDA), embarked on an effort to assess 

the relationship between gas resources and land use restrictions on Federal lands. The first area 

studied was the Greater Green River Basin (GGRB) of Wyoming and Colorado. DOE released 

its report on this assessment in June 20012

. Both the NPC study and the GGRB study were 

substantially less comprehensive that this study and report. While the GGRB study was being 

conducted, Congress reauthorized the EPCA in November 2000. Section 604 of this law required 

a similar study, to be led by DOI in cooperation with the USDA and DOE, which was to include 

an analysis of undiscovered oil and natural gas resources and proved oil and gas reserves for all 

onshore Federal lands in the United States. The text of Section 604 and the related conference 

report are given below. 

1.2 ENERGY POLICY AND CONSERVATION ACT LEGISLATION 

SEC. 604. SCIENTIFIC INVENTORY OF OIL AND GAS 

RESERVES 

(a) IN GENERAL--The Secretary of the Interior, in consultation with the Secretaries of 

Agriculture and Energy, shall conduct an inventory of all onshore Federal lands. The inventory 

shall identify--

(1) the United States Geological Survey reserve estimates of the oil and gas resources 

underlying these lands; and 

(2) the extent and nature of any restrictions or impediments to the development of such 

resources. 

(b) REGULAR UPDATE --Once completed, the USGS reserve estimates and the surface 

availability data as provided in subsection (a)(2) shall be regularly updated and made publicly 

available. 

(c) INVENTORY --The inventory shall be provided to the Committee on Resources of the 

House of Representatives and to the Committee on Energy and Natural Resources of the Senate 

within two years after the date of enactment of this section. 

(d) AUTHORIZATION OF APPROPRIATIONS --There are authorized to be appropriated 

such sums as may be necessary to implement this section3

. 

Congress further emphasized the urgency of this study during the appropriation process: 

2 “Federal Lands Analysis, Natural Gas Assessment, Southern Wyoming and Northwestern Colorado,

Study Methodology and Results,” June 2001, available on the DOE website:

http://fossil.energy.gov/techline/tl_ggrb_gas.shtml. 3

 Energy Policy and Conservation Act Amendments of 2000, P.L. 106-469, § 604, November 9, 2000.

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Introduction 

CONFERENCE REPORT ON H.R. 2217, DEPARTMENT OF INTERIOR AND RELATED 

AGENCIES APPROPRIATIONS ACT, 2002 

JOINT EXPLANATORY STATEMENT OF THE COMMITTEE OF CONFERENCE 

The managers agree to the following: 

... In light of recent attacks on the United States that have underscored the potential for 

disruptions to America’s energy supply, the managers believe this project should be considered a 

top priority for the Department4

. 

1.3 THE NATIONAL ENERGY POLICY, MAY 2001 

The President’s comprehensive National Energy Policy, issued May 2001, outlined more than a 

hundred recommendations to diversify and increase energy supplies, encourage conservation and 

improve energy distribution. The policy recommends a balanced approach that emphasizes 

renewable energy production and conservation as well as traditional fossil fuel production. Oil 

and natural gas was a major component of the President’s policy, in particular, examining ways to 

increase access to these resources. The Policy noted that some Federal lands, otherwise available 

for leasing have been legislatively or administratively withdrawn from leasing. The VicePresident’s National Energy Policy Development Group recommended: 

“...that the President direct the Secretary of the Interior to examine land status and lease 

stipulation impediments to Federal oil and gas leasing, and review and modify those where 

opportunities exist (consistent with the law, good environmental practice, and balanced use of 

other resources). 

Expedite the ongoing Energy Policy and Conservation Act study of impediments to 

federal oil and gas exploration and development, and 

Review public lands withdrawals and lease stipulations, with full public consultation, 

especially with the people in the region, to consider modifications where 

appropriate5

.” 

1.4 APPROACH 

A Steering Committee of senior staff from the participating agencies was formed to develop an 

effective process to complete the inventory. The Steering Committee identified five major 

geographic areas that had the greatest oil and natural gas development potential for analysis in the 

inventory. The five areas are the Paradox/San Juan Basins, the Uinta/Piceance Basins, the 

Greater Green River Basin, the Powder River Basin, and the Montana Thrust Belt (figure 1a). 

These five study areas contain most of the natural gas and much of the oil resource under public 

ownership in the onshore United States. The study areas are defined by the aggregation of the 

USGS oil and gas resource plays for each area. The energy resource and land status and 

stipulation data for these areas have been incorporated into a Geographic Information System 

(GIS) that allows derivative mapping and statistical analysis. 

4

 Congressional Record, October 11, 2001, House, p. H6526.

5

 National Energy Policy, Report of the National Energy Policy Development Group, May 2001.

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Introduction 

1.5 ROLES OF THE AGENCIES 

The EPCA designated the Departments of Interior, Agriculture, and Energy as responsible for the 

inventory. The Steering Committee provided guidance for conducting the studies, decisions 

concerning critical parameters, a review of the methodology developed by the one of the firms 

contracted for the inventory6

, and a review of the results. 

The Secretary of the Interior designated the BLM to be the lead agency for the EPCA inventory. 

The BLM maintains the oil and gas lease stipulation information for lands under its jurisdiction, 

as well as land status data for all Federally owned lands within the United States. 

The USGS, also a bureau of the DOI, contributed its assessments of undiscovered, technically 

recoverable oil and natural gas. The primary source of the oil and gas resource information used 

in this study was the USGS National Assessment of Oil and Gas Resources. 

The Secretary of Agriculture designated the USDA-FS, its primary land management agency, to 

contribute its information regarding oil and gas lease availability and leasing stipulations for 

lands within the National Forest System. 

The DOE, as author of the above-mentioned GGRB report, contributed its expertise and 

experience in guiding the design and analysis process for the EPCA inventory. DOE’s EIA 

contributed its analysis of proved reserves estimates for Federal lands. 

During the course of this study, members of the EPCA Steering Committee and contract 

personnel visited field offices within the various basins. BLM and USDA-FS personnel from 

over 70 offices (table 1a) participated in these visits. The purpose of these visits was to inform 

BLM and USDA-FS officials about the studies and to solicit input concerning lease stipulations 

and other issues of concern regarding oil and gas development. Data collection was performed 

during and following the field visits. 

1.6 INTENDED USE 

The EPCA inventory has been designed to be useful to a wide range of interests. In a broad 

sense, it gives a picture of where oil and gas is estimated to occur and an idea of what statutory 

and administrative constraints limit exploration and development. The EPCA inventory can be 

used by land management agencies to identify areas of high resource potential and then to 

examine land management decisions that affect access to those resources on Federal lands. Both 

the public and the land managers will have information about the magnitude of oil and natural gas 

losses due to access limitations which may be utilized in conjunction with other information 

about other resource values and the environment. 

The highly detailed stipulation data, brought together here for the first time, can be used in 

conjunction with the resource data by Congress, industry, environmental organizations, and other 

interested parties for a variety of analyses. Land withdrawals and oil and gas lease stipulations 

are designed to protect or mitigate adverse impacts to other valuable land resources. Land 

management agencies can analyze this information together with existing policies and procedures 

6 The principal firms contracted for the EPCA inventory were Advanced Resources International, 

Arlington, VA, and Premier Data Services, Denver, CO. 

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Introduction 

and look for opportunities to improve and enhance the decisions in their land use planning, 

leasing, and permitting processes. Agencies also can use this information to prioritize the need 

for additional data and analyses, and to identify where opportunities may exist for improving 

access to oil and gas resources. Overall, the EPCA inventory will provide additional information 

to help resolve development issues. It can help land management agencies to be more responsive 

to the needs of their customers. 

The primary product of the EPCA inventory is a GIS database composed of many layers of 

geographic data referenced by longitude and latitude. An important caution applies to the use and 

interpretation of the undiscovered energy resources. 

The caution is that the precise locations of undiscovered oil and natural gas resources are 

uncertain. Without extensive exploratory drilling, the assessment process is highly probabilistic. 

Therefore, specific assumptions were made concerning the undiscovered oil and natural gas 

resources within the inventory area. Over the last several decades, the USGS methodology has 

been the government’s standard for oil and gas resource estimation. The assessment process is a 

peer-reviewed statistical process that takes into consideration all available information to gain an 

understanding of the petroleum geology of the provinces being assessed. The USGS geologists 

using this information define the number of potential oil and gas plays within the provinces. The 

geologist then develops a probability distribution, which estimates the likelihood that a certain 

number and size of oil and natural gas accumulations are present within the province. There is 

additional uncertainty regarding the likelihood that a certain volume of oil and natural gas within 

each play is present. Therefore, for the purpose of the EPCA inventory it was assumed that there 

was a uniform distribution of the resources within a given play. It is important to note that for 

these reasons, the EPCA analysis does not imply that the locations of accumulations of 

undiscovered oil and natural gas resources are known to occur under specific land parcels. 

1.7 PRODUCTS/FUTURE DIRECTION 

The tables, data, maps (GIS products), and this summary report, which describes the 

methodology, applied standards, results, and land access issues, are available on CD-ROM and 

from the DOI (http://www.doi.gov) or BLM website (http://www.blm.gov/). 

EPCA Section 604 requires that all Federal lands of the onshore United States be inventoried. 

The Steering Committee anticipates that the EPCA inventory will be expanded in the future to 

additional areas where Federal lands overlie undiscovered resources, ultimate recovery 

appreciation (reserves growth), and proved oil and gas reserves. The information and analysis for 

already-studied areas will be updated as sufficient new information warrants. 

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Introduction 

Paradox/San Juan Study Area Greater Green River Study Area 

Albuquerque, NM BLM Field Office Ashley NF 

Ashley NF BLM Wyoming State Office 

Bureau of Reclamation Bridger-Teton NF 

Carson NF Bureau of Reclamation 

Cedar City, UT BLM Field Office Fishlake NF 

Cibola NF Kemmerer, WY BLM Field Office 

Dixie NF Lander, WY BLM Field Office 

Durango, CO BLM Field Office Little Snake, CO BLM Field Office 

Farmington, NM BLM Field Office Medicine Bow-Routt NF 

Fishlake NF Pinedale, WY BLM Field Office 

Grand Junction BLM Field Office Rawlins, WY BLM Field Office 

Grand Mesa/Uncompahgre/Gunnison NF Rock Springs, WY BLM Field Office 

Grand Staircase-Escalante National Monument Powder River Study Area 

Kanab, UT BLM Field Office Big Horn NF 

Manti-La Sal NF Billings, MT BLM Field Office 

Moab, UT BLM Field Office BLM Montana State Office 

Monticello, UT BLM Field Office BLM Wyoming State Office 

Price, UT BLM Field Office Black Hills NF 

Richfield, UT BLM Field Office Buffalo Gap National Grasslands 

Rio Grande NF Buffalo, WY BLM Field Office 

San Juan NF Casper, WY BLM Field Office 

Santa Fe NF Custer NF 

St. George, UT BLM Field Office Miles City, MT BLM Field Office 

Uncompahgre, CO BLM Field Office Nebraska NF 

Newcastle, WY BLM Field Office 

Oglala National Grasslands 

Uinta/Piceance Study Area 

Ashley NF 

BLM Utah State Office South Dakota BLM Field Office 

Bureau of Reclamation Thunder Basin National Grasslands 

Fishlake NF Montana Thrust Belt Study Area 

Glenwood Springs, CO BLM Field Office Beaverhead-Deerlodge NF 

Grand Junction, CO BLM Field Office Bitterroot NF 

Grand Mesa/Uncompahgre/Gunnison NF BLM Montana State Office 

Gunnison, CO BLM Field Office Bureau of Reclamation 

Little Snake, CO BLM Field Office Butte, MT BLM Field Office 

Manti-La Sal NF Dillon, MT BLM Field Office 

Medicine Bow-Routt NF Flathead NF 

Moab, UT BLM Field Office Gallatin NF 

Price, UT BLM Field Office Helena NF 

Richfield, UT BLM Field Office Kootenai NF 

Salt Lake, UT BLM Field Office Lewis and Clark NF 

Uinta NF Lewistown, MT BLM Field Office 

Uncompahgre, CO BLM Field Office Lolo NF 

Vernal, UT BLM Field Office Missoula, MT BLM Field Office 

White River NF 

White River, CO BLM Field Office 

NF = National Forest 

Table 1a BLM and Forest Service Offices Contacted for the Inventory 

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