Digital Elevation Model Data
The accepted framework layer for elevation in Montana is the USGS National Elevation Dataset. To reduce duplication of effort this data will no longer be available directly from the Montana State Library. Data can be downloaded from the USGS National Map Download Platform.
For Montana, 1/3 arc-second data and 1 arc-second data are available for the entire state. A handful of areas also have 1/9 arc-second and 1-meter data, with more becoming available in the near future as lidar is completed for the state. The ground resolution of 1-arc second data is approximately 30 meters, and the resolution of 1/3 arc-second data is approximately 10 meters, and the resolution of 1/9 arc second is approximately 3 meters.
The data are available as prepackaged, downloadable tiles (tile extent varies by product and data resolution) in GeoTiff and IMG formats. You may define custom areas of interest, but all of the tiles intersecting the area of interest will be included in the delivery (no clipping is performed).