| Ahtanum State Forest | |
| Map: | Washington |
| Location: | Yakima County, Washington, United States |
| Nearest City: | Yakima, Washington |
| Coordinates: | 46.5079°N -120.9217°W |
| Area: | 75000acres |
| Elevation Min: | 3150feet |
| Elevation Max: | 6981feet |
| Established: | 2005 |
| Administrator: | Washington State Department of Natural Resources |
| Website: | https://www.dnr.wa.gov/Ahtanum |
Ahtanum State Forest is a working forest and recreation area located in Yakima County, Washington. It covers approximately 75000acres and lies 30miles west of the city of Yakima. The forest borders the Yakama Indian Reservation to the south, and the name Ahtanum means “stream by long mountain” in the Yakama language.
The land comprising Ahtanum State Forest had previously been a checkerboard of public and private land. In 2005, the Washington State Department of Natural Resources (DNR) traded 3000acres of scattered land elsewhere for 12000acres of this private forest owned by two companies, Plum Creek Timber and Elk Haven Tree Farms. This "blocking up" allowed DNR to consolidate ownership of 35000acres of land in order to create Ahtanum State Forest. The Rocky Mountain Elk Foundation (RMEF) paid for $50,000 worth of appraisals to help complete the land exchange after DNR ran out of money until the next funding cycle.