Clarno is an unincorporated community in Wasco County, Oregon, United States. It is located along Oregon Route 218 near the John Day River. The community was named after Andrew Clarno, an early settler. The Clarno post office was established in 1894 in what was then Gilliam County, from which Wheeler County was later carved. After that, the post office wa…Clarno is an unincorporated community in Wasco County, Oregon, United States. It is located along Oregon Route 218 near the John Day River. The community was named after Andrew Clarno, an early settler. The Clarno post office was established in 1894 in what was then Gilliam County, from which Wheeler County was later carved. After that, the post office was sometimes in Wheeler County, on the east side of the river, or in Wasco County, on the west side, depending on who was postmaster. The office closed in 1949.