Seneca Map
Seneca is a city in Grant County, Oregon, United States. It is located in the Blue Mountains about 23 miles south of Canyon City, on U.S. Route 395, on the edge of the Malheur National Forest. The population was 223 at the 2000 census.
Seneca post office was established in 1895 and named by postmaster Minnie Southworth for her brother-in-law, prominent Portland judge Seneca Smith.
While early homesteaders moved into the valley in the late 1800s, Seneca only began growing in the 1929 when it became the northern terminus of the now-vacated Oregon and Northwestern Railroad, owned by the Edward Hines Lumber Company, which extended south to Burns. At that time, large-scale shipping of Ponderosa Pine logs from Seneca and the surrounding national forest began to the Hines sawmill in Hines. The company established a planing mill and railroad shops in Seneca, and it became essentially a company town. In 1940 Seneca's population was 275. Logging in the area began to decline in the 1970s, and the Hines company ceased operations of its lumber mills and railroad in 1984. The town was incorporated as a city in 1970 as lumber company control began to wane. According to the 1980 census, Seneca's population was 285. The estimated population in 2007 was 270.
Nearby cities include John Day, Canyon City.