The Rogue River-Siskiyou National Forest is a United States National Forest located on both sides of the border between the states of Oregon and California. The formerly separate Rogue River and Siskiyou National Forests were administratively combined in 2004. Now, the Rogue River-Siskiyou National Forest ranges from the crest of the Cascade Range west into the Siskiyou Mountains, covering almost . Forest headquarters are located in Medford, Oregon.
The National Forest is home to some stands of old growth, including Port Orford cedar and Douglas fir in the Copper Salmon area.
Rogue River National Forest is located in parts of five counties in southern Oregon and northern California. In descending order of land area they are Jackson, Klamath, Douglas, Siskiyou, and Josephine counties, with Siskiyou County being the only one in California. It has a land area of 628,443 acres (981.9 sq mi, or 2,543.2 km²). There are local ranger district offices located in Ashland, Butte Falls, Grants Pass, Jacksonville, and Prospect.
Siskiyou National Forest is located in parts of four counties in southwestern Oregon and northwestern California. In descending order of land area they are Curry, Josephine, and Coos counties in Oregon and Del Norte County in California. It has a land area of 1,094,726 acres (1,710.5 sq mi, or 4,430.2 km²). There are local ranger district offices located in Brookings, Cave Junction, Gold Beach, and Powers.