The Black Hills are a mountain range in Lake County,

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

. They are located to the immediate south of the community of

Christmas Valley Christmas Valley is an unincorporated community in Lake County, Oregon, United States. The community was named after nearby Christmas Lake, usually dry, east of the present town and the site of the former Lake post office, which ran from 1906 un ...

; just off of Old Lake Highway. It is a vent of the

Fort Rock–Christmas Lake Valley basin Fort Rock–Christmas Lake Valley is a basin of a former inland sea that existed in that region from Pliocene through late Pleistocene time. The Fort Rock basin maar field includes over 30 Phreatomagmatic eruption, hydrovolcanic landforms spre ...

volcanic field.

References

Mountain ranges of Oregon Mountain ranges of Lake County, Oregon Volcanoes of Oregon Volcanoes of the United States {{LakeCountyOR-geo-stub