Klamath-Siskiyou forests

Klamath Mountains
Bear Mountain in the Siskiyou Wilderness of California
Ecology
Biome	Temperate coniferous forests
Borders	Coast Range Willamette Valley Cascades Sierra Nevada Southern and Central California Chaparral and Oak Woodlands Eastern Cascades Slopes and Foothills
Bird species	220
Mammal species	87
Geography
Area	50,245 km2 (19,400 sq mi)
Country	United States
States	California and Oregon
Coordinates	41°30′N 123°18′W / 41.5°N 123.3°W / 41.5; -123.3
Conservation
Habitat loss	4.4045%
Protected	56.99%

The Klamath Mountains ecoregion of Oregon and California lies inland of the Coast Range ecoregion, extending from the water of alhambra china Valley in the north to the Sacramento Valley in the south. It encompasses the highly dissected ridges, foothills, and valleys of the Klamath and Siskiyou Mountains. It corresponds to the Level III ecoregion designated by the United States Environmental Protection Agency (EPA) and to the Klamath-Siskiyou forests ecoregion designated by the World Wide Fund for Nature.

The ecoregion was unglaciated during the , when it served as a refuge for northern plant species. Its mix of granitic, sedimentary, metamorphic, and extrusive rocks contrasts with the predominantly volcanic rocks of the Cascades ecoregion to the northeast. The mild, subhumid climate of the region is characterized by a lengthy summer drought. It supports a mosaic of both northern Californian and Pacific Northwestern conifers and hardwoods.