| Abstract
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This is large-scale vector topographic map data for parts of the upper Clark Fork basin. The data cover a 2000-foot wide strip along the Clark Fork from Milltown to Warm Springs, the Deer Lodge Valley between Warm Springs and Gregson, the city of Anaconda, the floodplain of Silver Bow Creek between Gregson and Butte, and the city of Butte.The data were digitized using photgrammetric techniques by Horizons, Inc., from aerial photos taken between 1984 and 1991. There are two copies of the data. One copy is an ESRI file geodatabase partitioned into feature datasets according to the photography dates. This data includes the text annotation provided by Horizons. The other copy is in ESRI shapefile format and does not include the annotation.The data themes include buildings, roads, railroads, hydrography, contour lines, poles, fences, spot elvations, control points, boreholes, pipelines, trees, and wooded areas. The area covered by data from various dates is shown in the Topo_ClarkFork_1a.gif image and Photo_Index dataset that are included in the distribution.Because the data were collected over a period of years, there are some areas that were digitized multiple times. To create a primary dataset that does not contain multiple representations of the same objects, the overlapping areas were removed from some of the feature classes and saved into a secondary "overlap" data collection. These are in the folders or feature datasets whose names start with "X", "Y", and "Z".These data were formerly available from the Montana State Library web site but were removed because they are potentially out of date. Please contact the Federal Superfund Bureau of the Montana Department of Environmental Quality if you want these data so they may tell you if newer or better data are available. If the data are not available from the Department of Environmental Quality, you may request a copy from the Montana State Library data archive.
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| Supplemental Information
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The feature classes have the following names according to their data themes:
building -- buildings and other structures
contour -- 10- or 25-foot contours
supcon -- 2- or 5- foot contours
spot -- spot elevations
control -- photogrammetry control points
borehole -- boreholes
culvert -- culverts
fence -- fences, walls, and guardrails
hydro_a -- drainage lines, shorelines, and water control structures
hydro_p -- area covered by lakes, streams, wetlands, and water control structures
pipeline -- pipelines
pole -- utility poles and signposts
railroad -- railroads
road -- roads, bridges, parking lots, and trails
tree -- individual tree locations
woods -- wooded areas
Milltown Reservoir was empty at the time the photos of the Milltown area were taken. The reservoir shoreline was digitized at the State Library from a 1:12,000 scale aerial photo taken in 1984. The shoreline location is approximate.
The contour interval of the data varies in different areas. The contour interval is 2 feet in the Milltown Reservoir, Anaconda, Smelter Hill, and Butte areas, 5 feet along the Clark Fork and in the Deer Lodge Valley, and 10 feet in the areas of the Yankee Doodle Tailings pond and the ridges north and east of Butte.
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