Geology topics
Research about Montana
Source-linked reports with geographic coverage including Montana.
Changes in quality of ground water in the Lincoln area, Montana, 1974-79
Water samples from representative shallow wells in the vicinity of Lincoln, Montana, were collected during March and June 1979 for analysis to evaluate changes in quality since 1974-75 and possible contamination by domestic or agricultural waste. All samples were suitable for drinking water with respect to the constituents tested. Tests for fecal coliform bacteria were negative. The concentrations of dissolved solids, composed mainly of calcium, magnesium, bicarbonate, and sulfate, were less than 300 milligrams per liter. Concentrations of sodium, potassium, and chloride were 3.5 milligrams per liter or less. From March to June, the maximum concentration of nitrite plus nitrate as nitrogen decreased from 0.57 to 0.29 milligram per liter and the mean concentrations decreased from 0.16 to 0.11 milligram per liter, probably as a result of dilution of ground water by snowmelt. The concentrations in samples from the same wells generally were less during 1979 than during 1974-75. Isolation of sewage effluent in shallow zones by hardpan, consumption of nutrients by abundant phreatophytes, filtration of bacteria by the soil or aquifer, and dilution by underflow and recharge evidently combine to maintain the quality of the well waters within acceptable limits.
Magnitude and chemical quality of base flow of Otter Creek, Tongue River, and Rosebud Creek, southeastern Montana, October 26-November 5, 1977
Hydrologic and chemical data were collected during base-flow conditions on three streams in southeastern Montana from October 26 to November 5, 1977, to characterize groundwater discharge. Maximum measured flow of Otter Creek, an interrupted stream, was 1.2 cubic feet per second. The water chemistry was dominated by sodium, magnesium, and sulfate ions, with a maximum dissolved-solids concentration of 3,540 milligrams per liter. Chemistry of groundwater inflow is dominated by sodium, magnesium, and sulfate. A discharge of 156 cubic feet per second from the Tongue River Reservoir into the Tongue River complicated interpretation of groundwater discharge to the reach downstream from the reservoir. Many reaches of gain and loss were observed along the Tongue River; the flow near the mouth was 233 cubic feet per second. Minor changes in quality of the base flow indicate groundwater discharges dominated by sodium, sulfate, and bicarbonate plus carbonate. Dissolved-solids concentration increased from 506 milligrams per liter near the dam to 630 milligrams per liter near the mouth. Maximum measured flow of Rosebud Creek was 19.0 cubic feet per second. Water quality in the upper reaches was dominated by magnesium, calcium , and bicarbonate, with dissolved-solids concentrations ranging from 560 to 703 milligrams per liter. Sodium, sulfate, and dissolved solids increase downstream.
Cross sections, Mammoth coal bed and Rehder split of Mammoth coal bed, Bull Mountain coal field, Montana
No abstract available.
Selected hydrologic and climatologic data from the Prairie Dog Creek Basin, southeastern Montana, water year 1979
Hydrologic and climatologic data are being collected in a 19-square-mile (49-square-kilometer) basin in southeastern Montana to provide a base for development, calibration, and verification of a precipitation-runoff model. The study area and data-collection stations within the area are shown on a map. A summary of data collected at each station during the first year, beginning in October 1978, is provided in tables. The data include precipitation, snow depth and water content, air temperature, relative humidity, wind run, solar radiation, soil temperature and moisture, stream discharge, chemical analyses of water, and sediment content.
Methodology for hydrologic evaluation of a potential surface mine: East Trail Creek Basin, Big Horn County, Montana
No abstract available.
Streamflow characteristics of the Hudson Bay and Upper Missouri River Basins, Montana, through 1979
Statistical summaries of streamflow data for selected gaging stations are presented in this report to aid in appraising the hydrology of the Hud son Bay and upper Missouri River basins in Montana. Streamflow records are presented for 122 gaging stations for the period of record of each station. Streamflow-record collection in the Missouri River basin began in 1890 at Fort Benton, Montana. For each streamflow-gaging station selected for this report, a brief description is given for station location, drainage area, period of record, revisions of previously published records, type and history of gages, regulation and diversions, average discharge, and extremes of discharge. These data are followed by tables of monthly and annual mean discharge, flood-frequency data, low-flow and high-flow frequency data, and flow-duration information.
Potential effects of urbanization on peak flows in Rattlesnake Creek, Missoula County, Montana
No abstract available.
Mean annual streamflow of selected drainage basins in the coal area of southeastern Montana
Streamflow characteristics of drainage basins within the Fort Union coal region of southeastern Montana were estimated to provide premining data for evaluating the future effects of mining on the environment. Estimated annual mean streamflow at 22 data-collection stations for water years 1975-77 ranged from 0 to 887 cubic feet per second. These estimates are based on miscellaneous-streamflow records at each station and continuous-streamflow records from other stations in the study area. Estimated mean annual streamflow for a 10-year period (water years 1968- 77) ranged from 0 to 572 cubic feet per second. These long-term estimates were based on data from stations near the study area having continuous- streamflow records. Estimated mean annual runoff in inches for selected drainage basins within the study area showed no discernible pattern. Many of the drainage basins had a mean annual runoff of less than 0.60 inch; the maximum observed mean annual runoff was 4.45 inches.
Modeled impacts of surface coal mining on dissolved solids in the Tongue River, southeastern Montana
A computer model has been developed for spatial and temporal simulation of streamflow and dissolved solids in the Tongue River from the Tongue River Dam to Miles City, Montana. User-defined plans of surface coal mining and agricultural development permit evaluation of potential changes in dissolved solids resulting from leaching of overburden material used to backfill mine pits and from withdrawal and return flow of irrigation water. Provision is made for simulation runs using increased streamflow from a proposed larger reservoir intended to replace the present Tongue River Reservoir. Simulations at mean streamflow indicated that mining 119,600 acres of federally leased coal tracts may increase by 4.8 percent the present annual dissolved-solids concentration in the Tongue River at Miles City. Simulations using the proposed Tongue River reservoir show substantial reductions in dissolved-solids concentration when paired with similar simulations using the present Tongue River Reservoir. When compared on a per-acre basis for the study area, the dewatering caused by irrigation increases dissolved-solids concentration more than the input of leachates from surface coal-mining operations. (USGS)
Water resources of the southern Powder River area, southeastern Montana
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Broad area forest fuels and topography mapping using digital Landsat and terrain data
A spatially registered digital data base of fuels and terrain information was generated for a test site on the Lolo National Forest in Montana. The data base was developed specifically for providing spatially relevant data to a mathematical fire behavior model developed by the Forest Service which integrates this information along with current weather data to produce realistic estimates of probable fire behavior. Methodologies for the processing and analysis of Landsat MSS and digital terrain data for the mapping of U.S. Forest Service fuel types were developed and demonstrated. Key elements in the mapping process were the development of a fuels terrain distribution model which provided a statistical description of the topographic distribution patterns of fuels within spectral classes, and secondly, the application of a layered classifier which incorporated the spectral and terrain data in a two-stage maximum likelihood classification framework for the mapping of fuels.