Highway 12

Highway 12 crosses Washington from Grays Harbor to the border with Idaho. Originating in Aberdeen at the junction with Highway 101, the highway splits from Highway 8 at Elma and follows a southeast course to Interstate 5. It coincides with Interstate 5 for about 20 miles to Napavine, where it heads east. Crossing the Washington's Cascade Mountains at White Pass Ski Area, it descends into Yakima. Following the Yakima Valley to Richland, it coincides with Interstate 82. At Richland, it crosses the Columbia River, bypasses Pasco and heads to Walla Walla. From there, it goes northeasterly through Waitsburg, Dayton and Pomeroy, eventually reaching Clarkston at the state line.