1:250,000 Scale Base Map Notes
You can zoom in by clicking any area of interest.
Click the "Enter Deep Map" or "Zoom Out" buttons to back out to Level Two.
The 1:250K Base Map is being assembled from multiple scans of 20 USGS maps, covering 8 minutes of longitude by 5 minutes of latitude. These are then combined to provide levels 3 and 4 of the "deep map" and to act as the reference framework for historic maps.