People have left a deep, indelible mark on the American West. The maps below show the extent of the human footprint in the 11 Western states.

White indicates areas with the least human impact, followed by green for places where the footprint is minimal, while orange and red areas are where people have done the most to transform native ecosystems. Please see this post for more details.

The human footprint map is based on the work of U.S. Geological Survey (USGS) scientists and was the basis of a 2008 paper in Ecological Applications by Matthias Leu, Steven E. Hanser, and Steven T. Knick. The scientists focused on 14 features, including the location of cities, farms, roads, canals, power lines, oil and gas wells, and human-caused wildfires.