1×2-Degree Quadrangle Geologic Maps

These maps cover 1 degree of latitude by 2 degrees of longitude and are the standard series for intermediate-scale geologic mapping. In this series, one inch on the map represents 250,000 inches, or about 4 miles, on the ground.

To obtain maps: Click on map area to view popup windows containing map information and links to purchase printed and/or digital copies, or to download a pdf map or a zip file with GIS data (if available).

Maps at other scales cover some of the gaps in 1×2-degree map coverage: 30’x60′ quadrangle geologic maps, 7.5′ quadrangle geologic maps. Other geologic maps include non-quadrangle geologic maps and national & state parks geologic maps.

Geologic Map Portal
View, create, save, and print custom maps, find out about geologic formations, and download GIS data.

GIS Map Data
Use GIS data to create specialized maps with a variety of spatial data.