The U.S. Geological Survey completed the following assessments of conventional and continuous oil and gas resources of the Devonian Three Forks Formation and Devonian and Mississippian Bakken Formation in the Williston Basin Province 5031 of North Dakota, Montana, and South Dakota.
2021 Bakken and Three Forks Formation Assessment

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 4.3 billion barrels of oil and 4.9 trillion cubic feet of gas (associated) in the Bakken and Three Forks Formations of the Williston Basin Province, North Dakota and Montana.
Williston Basin Assessments
The following are recent assessments of undiscovered oil and gas
- 2021 Continuous oil resources (Fact Sheet 2021-3058)
- 2020 Gas resources (Fact Sheet 2021-3024)
- 2020 Conventional resources of the upper Paleozoic strata (Fact Sheet 2021-3023)
- 2020 Pennsylvanian Tyler Formation (2020-3067)
- 2020 Conventional resources in the lower Paleozoic (Fact Sheet 2020-3063)
- 2013 Conventional and Continuous Assessment (Fact Sheet 2013-3013 and Open-File Report 2013-1094)
- 2008 Conventional and Continuous Assessment (Fact Sheet 2008-3092)
- 1995 Assessment (DDS 30)
Click here to access legacy downloadable data.
United States Assessments of Undiscovered Oil and Gas Resources
Below are data or web applications associated with this project.
USGS National and Global Oil and Gas Assessment Project - Williston Basin, Bakken and Three Forks Formations Continuous Assessment Unit Boundaries and Assessment Input Data Forms
USGS National and Global Oil and Gas Assessment Project - Williston Basin, Lower Paleozoic Conventional Assessment Unit Boundaries and Assessment Input Data Forms
USGS National and Global Oil and Gas Assessment Project - Williston Basin, Upper Paleozoic Conventional Assessment Unit Boundaries and Assessment Input Data Forms
USGS National and Global Oil and Gas Assessment Project - Williston Basin, Tyler Formation Assessment Unit Boundaries and Assessment Input Data Forms
USGS National and Global Oil and Gas Assessment Project - Williston Basin, Gas Assessment Unit Boundaries and Assessment Input Data Forms
Below are publications associated with this project.
Assessment of undiscovered continuous oil resources in the Bakken and Three Forks Formations of the Williston Basin Province, North Dakota and Montana, 2021
Assessment of undiscovered oil and gas resources in the Pennsylvanian Tyler Formation of the Williston Basin Province, 2020
Assessment of undiscovered conventional oil and gas resources in the lower Paleozoic of the Williston Basin Province, 2020
Assessment of undiscovered gas resources in the Williston Basin Province, 2020
Assessment of undiscovered conventional oil and gas resources of upper Paleozoic strata in the Williston Basin Province, 2020
Assessment of undiscovered continuous oil and gas resources in the Heath Formation, central Montana and western North Dakota, 2016
U.S. Geological Survey assessments of continuous (unconventional) oil and gas resources, 2000 to 2011
Map of assessed coalbed-gas resources in the United States, 2014
Procedure for calculating estimated ultimate recoveries of Bakken and Three Forks Formations horizontal wells in the Williston Basin
Input-form data for the U.S. Geological Survey assessment of the Devonian and Mississippian Bakken and Devonian Three Forks Formations of the U.S. Williston Basin Province, 2013
Assessment of undiscovered oil resources in the Bakken and Three Forks Formations, Williston Basin Province, Montana, North Dakota, and South Dakota, 2013
Assessment of undiscovered oil and gas resources of the Williston Basin Province of North Dakota, Montana, and South Dakota, 2010
- Overview
The U.S. Geological Survey completed the following assessments of conventional and continuous oil and gas resources of the Devonian Three Forks Formation and Devonian and Mississippian Bakken Formation in the Williston Basin Province 5031 of North Dakota, Montana, and South Dakota.
2021 Bakken and Three Forks Formation AssessmentUsing a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 4.3 billion barrels of oil and 4.9 trillion cubic feet of gas (associated) in the Bakken and Three Forks Formations of the Williston Basin Province, North Dakota and Montana.
Williston Basin AssessmentsThe following are recent assessments of undiscovered oil and gas
- 2021 Continuous oil resources (Fact Sheet 2021-3058)
- 2020 Gas resources (Fact Sheet 2021-3024)
- 2020 Conventional resources of the upper Paleozoic strata (Fact Sheet 2021-3023)
- 2020 Pennsylvanian Tyler Formation (2020-3067)
- 2020 Conventional resources in the lower Paleozoic (Fact Sheet 2020-3063)
- 2013 Conventional and Continuous Assessment (Fact Sheet 2013-3013 and Open-File Report 2013-1094)
- 2008 Conventional and Continuous Assessment (Fact Sheet 2008-3092)
- 1995 Assessment (DDS 30)
Click here to access legacy downloadable data.
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United States Assessments of Undiscovered Oil and Gas Resources
USGS Energy Resources Program provides periodic assessments of the oil and natural gas endowment of the United States and the World. This website provides access to new, prioritized, assessment results and supporting data for the United States, as part of the Energy Policy and Conservation Act (EPCA). - Data
Below are data or web applications associated with this project.
USGS National and Global Oil and Gas Assessment Project - Williston Basin, Bakken and Three Forks Formations Continuous Assessment Unit Boundaries and Assessment Input Data Forms
This data release contains the boundaries of assessment units and input data for the assessment of undiscovered oil and gas resources in the Bakken and Three Forks formations in the Williston Basin province in Montana, North Dakota and South Dakota. The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The AsseUSGS National and Global Oil and Gas Assessment Project - Williston Basin, Lower Paleozoic Conventional Assessment Unit Boundaries and Assessment Input Data Forms
This data release contains the boundaries of assessment units and input data for the assessment of undiscovered oil and gas resources in the Lower Paleozoic of the Williston Basin province in Montana, North Dakota and South Dakota. The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is defUSGS National and Global Oil and Gas Assessment Project - Williston Basin, Upper Paleozoic Conventional Assessment Unit Boundaries and Assessment Input Data Forms
This data release contains the boundaries of assessment units and input data for the assessment of undiscovered oil and gas resources in the Upper Paleozoic of the Williston Basin province in Montana, North Dakota and South Dakota. The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is defUSGS National and Global Oil and Gas Assessment Project - Williston Basin, Tyler Formation Assessment Unit Boundaries and Assessment Input Data Forms
This data release contains the boundaries of assessment units and input data for the assessment of undiscovered oil and gas resources in the Tyler formation of the Williston Basin province in Montana, North Dakota and South Dakota. The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is defUSGS National and Global Oil and Gas Assessment Project - Williston Basin, Gas Assessment Unit Boundaries and Assessment Input Data Forms
This data release contains the boundaries of assessment units and input data for the assessment of undiscovered gas resources in the Williston Basin province in Montana, North Dakota and South Dakota. The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is defined within the context of the - Publications
Below are publications associated with this project.
Filter Total Items: 17Assessment of undiscovered continuous oil resources in the Bakken and Three Forks Formations of the Williston Basin Province, North Dakota and Montana, 2021
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 4.3 billion barrels of oil and 4.9 trillion cubic feet of gas (associated) in the Bakken and Three Forks Formations of the Williston Basin Province, North Dakota and Montana.Assessment of undiscovered oil and gas resources in the Pennsylvanian Tyler Formation of the Williston Basin Province, 2020
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 161 million barrels of oil and 93 billion cubic feet of gas in the Tyler Formation of the Williston Basin Province, North Dakota.Assessment of undiscovered conventional oil and gas resources in the lower Paleozoic of the Williston Basin Province, 2020
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 83 million barrels of oil and 351 billion cubic feet of gas in lower Paleozoic strata of the Williston Basin Province, North Dakota, Montana, and South Dakota.Assessment of undiscovered gas resources in the Williston Basin Province, 2020
Using a geology-based assessment methodology, the U.S. Geological Survey estimated a mean of 2,438 billion (2.4 trillion) cubic feet of gas resources in the Williston Basin Province, in North Dakota, Montana, and South Dakota.Assessment of undiscovered conventional oil and gas resources of upper Paleozoic strata in the Williston Basin Province, 2020
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean oil and gas resources of 134 million barrels of oil and 81 billion cubic feet of gas in upper Paleozoic strata of the Williston Basin Province in North Dakota, Montana, and South Dakota.Assessment of undiscovered continuous oil and gas resources in the Heath Formation, central Montana and western North Dakota, 2016
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 884 million barrels of oil and 106 billion cubic feet of gas in the North-Central Montana and Williston Basin Provinces of central Montana and western North Dakota.U.S. Geological Survey assessments of continuous (unconventional) oil and gas resources, 2000 to 2011
From 2000 to 2011, the U.S. Geological Survey conducted 139 quantitative assessments of continuous (unconventional) oil and gas accumulations within the United States. This report documents those assessments more fully than previously done by providing detailed documentation of both the assessment input and output. This report also compiles the data into spreadsheet tables that can be more readilyMap of assessed coalbed-gas resources in the United States, 2014
This report presents a digital map of coalbed-gas resource assessments in the United States as part of the U.S. Geological Survey’s (USGS) National Assessment of Oil and Gas Project. Using a geology-based assessment methodology, the USGS quantitatively estimated potential volumes of undiscovered, technically recoverable natural gas resources within coalbed-gas assessment units (AUs). This is the tProcedure for calculating estimated ultimate recoveries of Bakken and Three Forks Formations horizontal wells in the Williston Basin
Estimated ultimate recoveries (EURs) are a key component in determining productivity of wells in continuous-type oil and gas reservoirs. EURs form the foundation of a well-performance-based assessment methodology initially developed by the U.S. Geological Survey (USGS; Schmoker, 1999). This methodology was formally reviewed by the American Association of Petroleum Geologists Committee on ResourceInput-form data for the U.S. Geological Survey assessment of the Devonian and Mississippian Bakken and Devonian Three Forks Formations of the U.S. Williston Basin Province, 2013
In 2013, the U.S. Geological Survey assessed the technically recoverable oil and gas resources of the Bakken and Three Forks Formations of the U.S. portion of the Williston Basin. The Bakken and Three Forks Formations were assessed as continuous and hypothetical conventional oil accumulations using a methodology similar to that used in the assessment of other continuous- and conventional-type asseAssessment of undiscovered oil resources in the Bakken and Three Forks Formations, Williston Basin Province, Montana, North Dakota, and South Dakota, 2013
Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered volumes of 7.4 billion barrels of oil, 6.7 trillion cubic feet of associated/dissolved natural gas, and 0.53 billion barrels of natural gas liquids in the Bakken and Three Forks Formations in the Williston Basin Province of Montana, North Dakota, and South Dakota.Assessment of undiscovered oil and gas resources of the Williston Basin Province of North Dakota, Montana, and South Dakota, 2010
Using a geology-based assessment method, the U.S. Geological Survey estimated mean undiscovered volumes of 3.8 billion barrels of undiscovered oil, 3.7 trillion cubic feet of associated/dissolved natural gas, and 0.2 billion barrels of undiscovered natural gas liquids in the Williston Basin Province, North Dakota, Montana, and South Dakota. The U.S. Geological Survey (USGS) recently completed a co - Web Tools
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