Siskiyou Mountains

The Siskiyou Mountains are a coastal mountain range in the northern Klamath Mountains in northwestern California and southwestern Oregon in the United States. They extend in an arc for approximately 100 miles (160 km) from east of Crescent City, California northeast along the north side of the Klamath River into Josephine and Jackson counties in Oregon. The mountain range forms a barrier between the watersheds of the Klamath River to the south and the Rogue River to the north.

These mountains are not the highest or most dramatic in the Klamath Mountains but are subtly beautiful, botanically diverse, and the wildest the region has to offer. Due to the relief so close to the Pacific Ocean, the peaks receive more precipitation than the surrounding land. This leads to forests that grow with heavy vegetation. Diversity abounds because western canyons can receive over 100 inches (2,500 mm) of rain in some winters while eastern areas are slightly more arid. Because the Siskiyous trend both north and south and then east and west, it holds species that range from coastal, like coast redwood, to Cascadian, like Alaska yellow-cedar and Pacific silver fir.

Much of the range is within the Rogue River-Siskiyou and Klamath national forests. The Pacific Crest Trail follows a portion of the ridge of the range. The Klamath-Siskiyou forests are noted for their high biodiversity.