Arapaho National Forest is a National Forest located in north-central Colorado, United States. The region is managed jointly with the Roosevelt National Forest and the Pawnee National Grassland from the United States Forest Service office in Fort Collins, Colorado. It has a wildlife refuge which manages a protection for all birds and mammals. The combined facility of 1,730,603 acres (7,004 km2) is denoted as ARP by the Forest Service. Separately, Arapaho National Forest consists of 723,744 acres (2,929 km2).

The Roosevelt National Forest is a National Forest located in north central Colorado. It is contiguous with the Colorado State Forest as well as the Arapaho National Forest and the Routt National Forest. The forest is administered jointly with the Arapaho National Forest and the Pawnee National Grassland from offices in Fort Collins, and is denoted by the United States Forest Service as ARP.