San Isabel National Forest is located in central Colorado.

The forest contains 19 of the state's 53 fourteeners, peaks over 14,000 feet (4,267 m) high, including Mount Elbert, the highest point in Colorado.

It has a total area of 1,120,233 acres (1,750.36 sq mi, or 4,533.42 km2) spread out over parts of eleven counties in central Colorado.

In descending order of land area it is located in Chaffee, Custer, Lake, Huerfano, Fremont, Pueblo, Saguache, Las Animas, Park, Costilla, and Summit counties.

There are local ranger district offices located in Cañon City, Leadville, and Salida.