Grouse, also known as Grouse Flat, is an unincorporated community in Wallowa County, Oregon, located less than a mile south of the border with Washington. History The town was named for the abundance of grouse in the area. The Grouse post office was established on January 28, 1896, and Samuel M. Silver was the first postmaster. References Unincorporated communities in Wallowa County, Oregon Unincorporated communities in Oregon 1896 establishments in Oregon Populated places established in 1896