Tim has been a hydrologist with the USGS in Cheyenne, Wyoming, beginning as a student in 1990. He was the National Water Quality Assessment (NAWQA) Yellowstone River Basin Groundwater Specialist from 1997 to 2007. In 2002, Tim was named the Groundwater Specialist for Wyoming, and in 2012 was assigned to be the Groundwater Specialist for Montana as well.
Tim has investigated a wide variety of local (site-specific) and regional (basin or larger) scale groundwater studies. These studies have included both the physical and chemical aspects of hydrogeology, with many integrating both aspects. Detailed characterization of groundwater systems at various scales through the utilization and integration of physical (for example, detailed geologic/lithologic/stratigraphic examination and borehole geophysics) and chemical methods (groundwater chemistry) is of particular interest to Tim.
Tim is recognized for his knowledge of Wyoming’s hydrogeology, and is a licensed Professional Geologist in the state (PG-3349).
Science and Products
Wyoming Landscape Conservation Initiative: Water Resources
Hydrologic Assessment of the Blackfeet Reservation, Montana
Williston and Powder River Basins Groundwater Availability Study
Hydrologic Assessment with an Emphasis on Water Quality within the Lame Deer Creek Watershed, Northern Cheyenne Indian Reservation, Montana
Atmospheric-loading frequency response functions and groundwater levels filtered for the effects of atmospheric loading and solid Earth tides for three USGS monitoring wells, southeastern Laramie County, Wyoming, 2014-2017
Generalized potentiometric surface, estimated depth to water, and estimated saturated thickness of the High Plains aquifer system, March–June 2009, Laramie County, Wyoming
U.S. Geological Survey and Blackfeet Water Department Hydrologic Assessment of the Blackfeet Indian Reservation, Montana
Potential effects of energy development on environmental resources of the Williston Basin in Montana, North Dakota, and South Dakota—Water resources
Geologic and hydrogeologic characteristics of the White River Formation, Lance Formation, and Fox Hills Sandstone, northern greater Denver Basin, southeastern Laramie County, Wyoming
Groundwater availability of the Williston Basin, United States and Canada
U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2015 annual report
U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2014 annual report
Hydrogeology, groundwater levels, and generalized potentiometric-surface map of the Green River Basin lower Tertiary aquifer system, 2010–14, in the northern Green River structural basin
Geologic and hydrogeologic characteristics of the Ogallala Formation and White River Group, Belvoir Ranch near Cheyenne, Laramie County, Wyoming
Pesticides in Wyoming Groundwater, 2008-10
Hydrologic and geochemical data collected near Skewed Reservoir, an impoundment for coal-bed natural gas produced water, Powder River Basin, Wyoming
Pesticides in Ground Water of Wyoming, 1995-2006
Occurrence of Pesticides in Ground Water of Wyoming, 1995-2006
Science and Products
- Science
Wyoming Landscape Conservation Initiative: Water Resources
The Wyoming Landscape Conservation Initiative is a long-term science-based effort to assess and enhance aquatic and terrestrial habitats at a landscape scale in southwest Wyoming, while facilitating responsible development through local collaboration and partnerships. The WLCI is an interagency working group of partners that is beginning the process of establishing a much larger coalition of...Hydrologic Assessment of the Blackfeet Reservation, Montana
The Blackfeet Nation seeks an increased scientific understanding of the water resources within the Blackfeet Reservation of northwestern Montana. Hydrologic information is needed in order to make informed water management decisions as the Blackfeet Nation moves forward with implementation of the Blackfeet Water Rights Compact as new water-use projects are initiated and as the Blackfeet Irrigation...Williston and Powder River Basins Groundwater Availability Study
The development of two nationally important energy-producing areas, the Williston structural basin (containing the Bakken Formation) and Powder River structural basin, provide a critical opportunity to study the water-energy nexus within a groundwater context. Large volumes of water are needed for energy development in these basins. The hydraulically connected aquifers in the regional glacial...Hydrologic Assessment with an Emphasis on Water Quality within the Lame Deer Creek Watershed, Northern Cheyenne Indian Reservation, Montana
The Lame Deer Creek watershed of the Northern Cheyenne Reservation in southeastern Montana encompasses about 82 square miles and is home to the community of Lame Deer. Local water resources within the Lame Deer Creek watershed include Lame Deer Creek and groundwater within unconsolidated sediments and bedrock aquifers. In 2017 the U.S. Geological Survey, in cooperation with the Northern Cheyenne... - Data
Atmospheric-loading frequency response functions and groundwater levels filtered for the effects of atmospheric loading and solid Earth tides for three USGS monitoring wells, southeastern Laramie County, Wyoming, 2014-2017
The data include atmospheric-loading frequency response functions (table 1) and filtered detrended and reconstructed (trends restored) groundwater levels (tables 2-4) computed for selected, parsed time series for three USGS monitoring wells [BR-1 (USGS site 410233104093203); LN-1 (USGS site 410233104093202); and FH-1 (USGS site 410233104093201)], and the associated hourly resampled water-level and - Maps
Generalized potentiometric surface, estimated depth to water, and estimated saturated thickness of the High Plains aquifer system, March–June 2009, Laramie County, Wyoming
The High Plains aquifer system, commonly called the High Plains aquifer in many publications, is a nationally important water resource that underlies a 111-million-acre area (173,000 square miles) in parts of eight States including Wyoming. Through irrigation of crops with groundwater from the High Plains aquifer system, the area that overlies the aquifer system has become one of the major agricul - Publications
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U.S. Geological Survey and Blackfeet Water Department Hydrologic Assessment of the Blackfeet Indian Reservation, Montana
The Blackfeet Nation seeks an increased scientific understanding of the water resources within the Blackfeet Indian Reservation of northwestern Montana. Hydrologic information is needed to better inform water-management decisions as the Blackfeet Nation implements the Blackfeet Water Rights Compact, initiates new water-use projects, and improves the Blackfeet Irrigation Project.The U.S. GeologicalAuthorsSean M. Lawlor, Rodney R. Caldwell, Timothy T. Bartos, Brett PricePotential effects of energy development on environmental resources of the Williston Basin in Montana, North Dakota, and South Dakota—Water resources
The Williston Basin has been a leading oil and gas producing area for more than 50 years. While oil production initially peaked within the Williston Basin in the mid-1980s, production rapidly increased in the mid-2000s, largely because of improved horizontal (directional) drilling and hydraulic fracturing methods. In 2012, energy development associated with the Bakken Formation was identified as aAuthorsTimothy T. Bartos, Steven K. Sando, Todd M. Preston, Gregory C. Delzer, Robert F. Lundgren, Rochelle A. Nustad, Rodney R. Caldwell, Zell E. Peterman, Bruce D. Smith, Kathleen M. Macek-Rowland, David A. Bender, Jill D. Frankforter, Joel M. GallowayGeologic and hydrogeologic characteristics of the White River Formation, Lance Formation, and Fox Hills Sandstone, northern greater Denver Basin, southeastern Laramie County, Wyoming
In cooperation with the Wyoming State Engineer’s Office, the U.S. Geological Survey studied the geologic and hydrogeologic characteristics of Cenozoic and Upper Cretaceous strata at a location in southeastern Laramie County within the Wyoming part of the Cheyenne Basin, the northern subbasin of the greater Denver Basin. The study aimed to improve understanding of the aquifers/aquifer systems in thAuthorsTimothy T. Bartos, Devin L. Galloway, Laura L. Hallberg, Marieke Dechesne, Sharon F. Diehl, Seth L. DavidsonGroundwater availability of the Williston Basin, United States and Canada
Executive SummaryThe Williston Basin of the Northern Great Plains is a sedimentary basin—a geologic bowl-like structure filled with layered sedimentary rocks dating as far back as the Paleozoic age. The basin, which is nationally important for the production of energy resources, spans Montana, North Dakota, and South Dakota in the United States, and Manitoba and Saskatchewan in Canada. The three uAuthorsAndrew J. Long, Joanna N. Thamke, Kyle W. Davis, Timothy T. BartosU.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2015 annual report
This is the eighth annual report highlighting U.S. Geological Survey (USGS) science and decision-support activities conducted for the Wyoming Landscape Conservation Initiative (WLCI). The activities address specific management needs identified by WLCI partner agencies. In 2015, USGS scientists continued 24 WLCI projects in 5 categories: (1) acquiring and analyzing resource-condition data to form aAuthorsZachary H. Bowen, Cameron L. Aldridge, Patrick J. Anderson, Timothy J. Assal, Timothy T. Bartos, Anna D. Chalfoun, Geneva W. Chong, Marie K. Dematatis, Cheryl A. Eddy-Miller, Steven L. Garman, Stephen S. Germaine, Collin G. Homer, Matthew J. Kauffman, Christopher C. Huber, Daniel J. Manier, Cynthia P. Melcher, Kirk A. Miller, Tamar Norkin, Lindsey E. Sanders, Annika W. Walters, Anna B. Wilson, Teal B. WyckoffU.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2014 annual report
This is the seventh report produced by the U.S. Geological Survey (USGS) for the Wyoming Landscape Conservation Initiative (WLCI) to detail annual activities conducted by the USGS for addressing specific management needs identified by WLCI partners. In FY2014, there were 26 projects, including a new one that was completed, two others that were also completed, and several that entered new phases orAuthorsZachary H. Bowen, Cameron L. Aldridge, Patrick J. Anderson, Timothy J. Assal, Timothy T. Bartos, Laura R Biewick, Gregory K. Boughton, Anna D. Chalfoun, Geneva W. Chong, Marie K. Dematatis, Cheryl A. Eddy-Miller, Steven L. Garman, Steve Germaine, Collin G. Homer, Christopher Huber, Matthew J. Kauffman, Natalie Latysh, Daniel J. Manier, Cynthia P. Melcher, Alexander Miller, Kirk A. Miller, Edward M. Olexa, Spencer Schell, Annika W. Walters, Anna B. Wilson, Teal B. WyckoffHydrogeology, groundwater levels, and generalized potentiometric-surface map of the Green River Basin lower Tertiary aquifer system, 2010–14, in the northern Green River structural basin
In cooperation with the Bureau of Land Management, groundwater levels in wells located in the northern Green River Basin in Wyoming, an area of ongoing energy development, were measured by the U.S. Geological Survey from 2010 to 2014. The wells were completed in the uppermost aquifers of the Green River Basin lower Tertiary aquifer system, which is a complex regional aquifer system that provides wAuthorsTimothy T. Bartos, Laura L. Hallberg, Cheryl A. Eddy-MillerGeologic and hydrogeologic characteristics of the Ogallala Formation and White River Group, Belvoir Ranch near Cheyenne, Laramie County, Wyoming
The geologic and hydrogeologic characteristics of Tertiary lithostratigraphic units (Ogallala Formation and White River Group) that typically compose or underlie the High Plains aquifer system in southeastern Wyoming were described physically and chemically, and evaluated at a location on the Belvoir Ranch in Laramie County, Wyoming. On the basis of this characterization and evaluation, three TertAuthorsTimothy T. Bartos, Sharon F. Diehl, Laura L. Hallberg, Daniel M. WebsterPesticides in Wyoming Groundwater, 2008-10
Groundwater samples were collected from 296 wells during 1995-2006 as part of a baseline study of pesticides in Wyoming groundwater. In 2009, a previous report summarized the results of the baseline sampling and the statistical evaluation of the occurrence of pesticides in relation to selected natural and anthropogenic (human-related) characteristics. During 2008-10, the U.S. Geological Survey, inAuthorsCheryl A. Eddy-Miller, Timothy T. Bartos, Michelle L. TaylorHydrologic and geochemical data collected near Skewed Reservoir, an impoundment for coal-bed natural gas produced water, Powder River Basin, Wyoming
The Powder River Structural Basin is one of the largest producers of coal-bed natural gas (CBNG) in the United States. An important environmental concern in the Basin is the fate of groundwater that is extracted during CBNG production. Most of this produced water is disposed of in unlined surface impoundments. A 6-year study of groundwater flow and subsurface water and soil chemistry was conductedAuthorsRichard W. Healy, Cynthia A. Rice, Timothy T. BartosPesticides in Ground Water of Wyoming, 1995-2006
In 1991, members of local, State, and Federal governments, as well as industry and interest groups, formed the Ground-water and Pesticides Strategy Committee (GPSC) to prepare the State of Wyoming Generic Management Plan for Pesticides in Ground Water. Little existing information was available describing pesticide occurrence in ground water; therefore, statewide baseline ground-water sampling wasAuthorsCheryl A. Eddy-Miller, Timothy T. Bartos, Laura L. HallbergOccurrence of Pesticides in Ground Water of Wyoming, 1995-2006
Little existing information was available describing pesticide occurrence in ground water of Wyoming, so the U.S. Geological Survey, in cooperation with the Wyoming Department of Agriculture and the Wyoming Department of Environmental Quality on behalf of the Wyoming Ground-water and Pesticides Strategy Committee, collected ground-water samples twice (during late summer/early fall and spring) fromAuthorsTimothy T. Bartos, Cheryl A. Eddy-Miller, Laura L. Hallberg