Tieton Main Canal, also called Tieton Canal, Yakima-Tieton Irrigation Canal and Yakima Tieton Main Canal, is a 12-mile (19 km) long irrigation canal on the Tieton River in Washington state. It was cut by hand in 1906 with federal funding, one of the first canals created under the 1902 Reclamation Act, and opened in 1907. The canal was shut down for 19 days due to ash from the 1980 eruption of Mount St. Helens and again during the Rimrock Retreat Fire in 2024. Two miles of the canal are through tunnels, including 3,810-foot (1,160 m) long North Fork Tunnel.