Secondary State Highway 11C

Two different routes have been designated as SSH 11C at different times

Earlier SSH 11C

The earlier route was added to the state highway system in 1937. This route began at Jct PSH 11 (US 395) at Sprague and headed SE via Ewan, and St. John, ending at Jct PSH 3 (US 195) at Steptoe.

In 1943, the state legislature added a proposed extension of PSH 18 from Ritzville easterly to Jct SSH 11C near Ewan to the state highway system. At the same time, that portion of SSH 11C from the Ewan area to Steptoe was redesignated as part of PSH 18.

The Sprague to Ewan section of SSH 11C was added to PSH 18 in 1953. However, the wording of state law was not changed to actually drop the SSH 11C designation from this highway until 1961, i.e. state law described the state highway from Sprague to Steptoe as both SSH 11C and PSH 18 from 1953 to 1961. The state highway from Sprague to Steptoe is now designated as SR 23.

Later SSH 11C

The later route was added to the state highway system in 1961. This route began on the Hanford Reservation at Jct SSH 11A (now SR 24) near Cold Creek and headed southeasterly to Jct SSH 3R (now SR 224) in Richland. The actual SSH 11C roadway did not open to traffic until around 1967 and has, since opening, always been signed as SR 240.