San Isabel National Forest is located in central Colorado. The forest contains 19 of the state's 54 fourteeners, peaks over 14,000 feet (4,300 m) high, including Mount Elbert, the highest point in Colorado.
It is one of eleven national forests in the state of Colorado and contains the Sawatch Range, the Collegiate Peaks, and Sangre de Cristo Range. 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.