The Siskiyou Mountains are a coastal subrange of the Klamath Mountains, and located in northwestern California and southwestern Oregon in the United States. They extend in an arc for approximately 100mi 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 of the Klamath Mountains, but 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 100in of rain in some winters while eastern areas are slightly more arid. Since the Siskiyous trend both north to south and then east to west, they hold species that range from coastal, like Coast Redwood, to Cascadian, like Alaska Yellow-Cedar and Pacific Silver Fir.