Rectified Geologic Map Images of the Northern Rockies, 1:250k to 1:100k Scale

42 georeferenced raster images of geologic maps covering parts of the Northern Rocky Mountains in Idaho, Montana, Washington, and Wyoming. Selected paper maps and digital files were scanned, cropped, rectified, and converted to MrSID format for visual comparison in a GIS. The USGS summary indicates these images are intended for visual overlay but not for spatial analysis or querying.

Use Cases

• Visually comparing published geologic boundaries with other geospatial layers based on the rectified raster images.
• Referencing historical geologic interpretations for field work planning using the included searchable PDF of map unit descriptions.
• Creating base visualizations for presentations or reports using the provided TIFF and MrSID image formats.

Strengths

• Contains 42 distinct georeferenced map images.
• Maps cover a range of scales from 1:250,000 to 1:100,000.
• Includes a searchable PDF file organizing map unit descriptions, names, labels, and citations.

Limitations

• Rectified images cannot be queried or used for spatial analysis, limiting GIS utility.
• Column-level documentation is absent; field semantics must be inferred after download.
• Last update date is unknown; freshness unverified.

Provenance

Source

USGS (summary provided by USGS), platform: nasa_earthdata, organization: CEOS_EXTRA

Collection Method

Original paper maps were scanned or digital PDF/EPS files were converted to TIFF, then cropped and rectified using ArcMap 8.

Geography

Northern Rocky Mountains and adjacent areas in Idaho, Montana, Washington, and Wyoming, USA.