Fort Klamath is an unincorporated community between Crater Lake National Park and Upper Klamath Lake in Klamath County, Oregon, United States.The community is located about a mile northwest of Fort Klamath, the Oregon Trail military outpost.Fort Klamath post office was established January 6, 1879.[1] This region experiences warm (but not hot) and dry summers, with no average monthly temperatures above 71.6 °F.This Klamath County, Oregon state location article is a stub.