From purpose and scope: The purpose of this study was to describe existing hydrologic systems, to obtain data on the water quality in the area, and to assess potential impacts of surface coal mining on local water resources.

From purpose and scope: The purpose of this report is to summarize and evaluate water-quality data acquired from streams within the study area from October 1975 through September 1981. This report updates data collected at 9 stations during the initial study and provides new data for 14 stations.

From purpose and scope: The purpose of this report is to describe the existing hydrologic and water-quality conditions of the shallow ground-water system above the Bearpaw Shale and to describe the surface-water resources in the Fort Union coal region of east-central Montana. The objective of this study was to provide premining data that would be useful for water-resources planning.

From purpose and scope: The purpose of this report is (1) to describe the flow system within the Kootenai Formation, which is the principal aquifer, and (2) to describe the interaction between the Kootenai and overlying and underlying Mesozoic aquifers.

From introduction: The purpose of this report is to provide estimates of 100-year flood discharges at selected sites in Glacier and Yellowstone National Parks. Estimates for streams with contributing drainage areas outside Glacier National Park were determined using only the contributing drainage area in the park.

From introduction: The purpose of this report is to provide methods for estimating mean annual runoff and peak discharges for ungaged streams in northeastern and western Montana.

From introduction: The purpose of this report is to describe the channel-geometry technique and to present equations for estimating mean annual runoff and peak flows for ungaged streams in southeastern Montana.

From purpose and scope: The purpose of this report is to present biological data and to compare the physical, chemical, and biological data to water-quality criteria that are desirable for the proposed reservoir uses.

From purpose and scope: The purpose of this report is to summarize and evaluate fluvial-sediment data collected in the study area by the U.S. Geological Survey. The principal products of this report are sediment concentration and load statistics, sediment-transport curves, calculated mean annual sediment yields at selected stations, and an areal sediment-yield map. A secondary purpose is to describe sediment relationships between stations and basins and to identify environmental factors that are important in determining sediment yield.

From purpose and scope: The purpose of this study was to describe existing hydrologic systems, to obtain data on the water quality in the area, and to assess potential impacts of surface coal mining on local water resources. Specific objectives of the study were to: (1) Identify ground-water resources and use; (2) identify surface-water resources and runoff characteristics; (3) determine chemical quality of the ground-water resources; (4) identify probable impacts on existing water resources by mining operations; and (5) evaluate the potential for reclamation of local water resources.

From abstract: The Snider Creek area of the Rosebud and Ashland coal fiends contains strippable reserves of Federal coal that have been identified for potential lease sale. A hydrologic study has been conducted in the potential lease area to describe the existing hydrologic systems and to assess potential impacts of surface coal mining on local water resources.

From abstract: During fiscal years 1978 through 1981, the U.S. Geological Survey contracted for the acquisition and analysis of hydrologic data from 104 surface water stations, 26 ground water stations, and 15 precipitation gages as well as for several hundred miscellaneous surface water measurements of flow and water quality. The work was performed in Montana, North Dakota, Wyoming, Utah, New Mexico, and Oklahoma, terminating at the end of the fiscal year 1981. This report is an assessment of this contracting effort from the standpoint of cost and of quality control measures employed to ensure an acceptable product.

From objectives and scope: This study was undertaken in response to U.S. Bureau of Land Management concerns for the water resources of the Wibaux-Beach area in the event of lignite mining. The objectives of the study were to: (1) Define the stratigraphic sequence within a few hundred feet above and below the minable lignite; (2) define the premining hydrologic and geochemical regime of the Wibaux-Beach deposit area; and (3) describe some of the hydrologic implications of the strip-mining process. A fourth objective, the establishment of historical data base with which to access any modifications to the system attributable to future mining, was accomplished as a byproduct of the other three.

From introduction: The overall purpose of this study were twofold: (1) To determine where greatest yielding wells at shallowest depths would produce water of suitable quality for municipal and industrial supplies; and (2) to determine regional effects of additional water development on the hydrologic system.

Abstract: This report lists the machine-readable data files developed for the Madison Limestone and Northern Great Plains Regional Aquifer System Analysis (RASA) projects that are stored on magnetic tape and available from the U.S. Geological Survey. Record format, file content, and size are given for: (1) Drill-stem-test data for Paleozoic and Mesozoic formations; (2) geologic data from the Madison Limestone project; (3) data sets used in the regional simulation model; (4) hydraulic-head data for the Lower and Upper Cretaceous aquifers; and (5) geologic data for Mesozoic formations of the Northern Great Plains.

From introduction: In 1978 the U.S. Geological Survey began a 4-year study of aquifers in the northern Great Plains. The purpose of this map, which is a product of that study, is to show the altitude of the top of the "Dakota sandstone" (drillers' term).

From introduction: In 1978 the U.S. Geological Survey began a 4-year study of aquifers in the northern Great Plains. The purpose of this map, which is a product of that study, is to show the altitude of the top of the Eagle Sandstone.

Introduction: In 1978 the U.S. Geological Survey began a 4-year study of aquifers in the northern Great Plains. The purpose of this map, which is a product of that study, is to show the altitude of the top of the Fox Hills-lower Hell Creek aquifer. Other maps show the total thickness (Feltis, 1982a). cumulative thickness of sandstone (Feltis, 1982b), and potentiometric surface of water (Levings, 1982) of the Fox Hills-lower Hell Creek aquifer. These maps are part of a series that describes the geology and potentiometric surface of selected rock units of Jurassic or younger age in the plains area of Montana.

From introduction: In 1978 the U.S. Geological Survey began a 4-year study of aquifer in the northern Great Plains. The purpose of this map, which is a product of that study, is to show the altitude of the top of the Judith River Formation.

Introduction: In 1978 the U.S. Geological Survey began a 4-year study of aquifers in the northern Great Plains. The purpose of this map, which is a product of that study, is to show the altitude of the top of the Lakota Formation and equivalent rocks. Other maps show the total thickness (Feltis, 1982a), cumulative thickness of sandstone (Feltis, 1982b), and potentiometric surface of water (Levings, 1982) in the Lakota Formation and equivalent rocks. These maps are part of a series that describes the geology and potentiometric surface of selected rock units of Jurassic or younger age in the plains area of Montana.

From introduction: In 1978 the U.S. Geological Survey began a 4-year study of aquifers in the norther Great Plains. The purpose of this map, which is a product of that study, is to show the altitude of the top of the Swift Formation.

From introduction: In 1978 the U.S. Geological Survey began a 4-year study of aquifers in the northern Great Plains. The purpose of this map, which is a product of that study, is to show the cumulative thickness of sandstone in the "Dakota sandstone" (drillers' term).

From introduction: In 1978 the U.S. Geological Survey began a 4-year study of aquifers in the northern Great Plains. The purpose of this map, which is a product of that study, is to show the cumulative thickness of sandstone in the combined Eagle Sandstone and Telegraph Creek Formation.

Introduction: In 1978, the U.S. Geological Survey began a 4-year study of aquifers in the northern Great Plains. The purpose of this map, which is a product of that study, is to show the cumulative thickness of sandstone in the Fox Hills-lower Hell Creek aquifer. Other maps show the altitude of the top (Feltis, 1982a), total thickness (Feltis, 1982b), and potentiometric surface of water (Levings, 1982) of the Fox Hills-lower Hell Creek aquifer. These maps are part of a series that describes the geology and potentiometric surface of selected rock units of Jurassic or younger age in the plains area of Montana.