OR 205 begins at the Roaring Springs Ranch as a continuation of Catlow Valley Road, which connects with Nevada State Route 292 near Denio, Nevada. It travels north along the edge of the Catlow Valley and turns east to enter Frenchglen in Blitzen Valley. The highway continues north on the rim of Jackass Mountain through parts of the Malheur National Wildlife Refuge, crossing between Harney Lake and Malheur Lake in Sunset Valley. After briefly turning west to cross Wrights Point, OR 205 continues due north through Harney Valley and terminates at a junction with OR 78 east of Burns.