The highway extends northeast and east as Dayton Airport Road from the Washington Corrections Center through rural Mason County to an intersection with U.S. Route 101 (US 101) northwest of Shelton.

SR 102 begins as the two-lane Dayton Airport Road at an intersection with the Washington Corrections Center access road and travels northeast into a heavily wooded area.

The highway turns east, passing the Washington State Patrol Academy and The Ridge Motorsports Park, before it ends at an intersection with US 101 north of Sanderson Field and west of Turtle Lake.

The entire highway is located northwest of Shelton in unincorporated Mason County.

[4] SR 102 was established in 1984 on the existing Dayton Airport Road northwest of Shelton.