Summerville is a city in Union County, Oregon, United States. The population was 135 at the 2010 census. Summerville was platted on September 20, 1873, along Ruckle Road by William H. Patten. Patten had a freight depot along Ruckles Road, only the second road over the Blue Mountains, which was a popular route over the Blue Mountains until it washed out in 1884. Speculators and investors then moved to Elgin, Oregon. An 1888 Sanborn map, the first of four of the city, shows an opera hall, bank, livery, drugstore, as well as other stores. In 1888, half of the main street buildings were destroyed in a fire, but were rebuilt soon after. As the town was already in a sharp commercial decline by 1910, buildings that were destroyed after then were not replaced. In 1890, the population was 280 people.