The Yakima Herald-Republic reports the mudslide was caused by heavy rains Saturday night.
The Washington Department of Transportation says the closure stretches from the junction with Highway 97 south of Goldendale east to milepost 167 near Paterson at the junction of State Route 221.
Highway crews are assessing the situation.
State Route 14 in the affected area is open to local traffic only. The State Patrol says motorists may detour via U.S. 97 and SR 221.