Secondary State Highway 7E

SSH 7E was added to the state highway system in 1955. This route began in Moses Lake at Jct PSH 18 (US 10) and headed northeasterly to Jct PSH 7 (now SR 28) west of Odessa. The law creating this highway provided that no existing county roads would be maintained by the state as a temporary route of SSH 7E until the permanent route was completed by the state and opened to traffic.

In 1959, the legal definition of SSH 7E was changed. The route definition was reversed, with the beginning now described as being on the Odessa end. By this time the I-90 Moses Lake Bypass was under construction. SSH 7E was extended through Moses Lake to a junction with the new PSH 18 (I-90/US 10) on the SW side of Moses Lake by 1959 legislation. Today, SSH 7E is SR 171. The portion of SR 171 from Jct SR 17 on the NE side of Moses Lake to Jct SR 28 west of Odessa has not yet been built as a state highway as of 2001.