The mud oozed across a highway in Yakima County near Naches, Wash., Sunday and flowed into the Naches River, diverting its course, the Yakima (Wash.) Herald-Republic reported.
The newspaper said the mudslide forced the closure of a 47-mile stretch of state Highway 410 between Mount Rainier National Park's Lake Tipsoo to its junction with U.S. Highway 12 west of Naches.
Jim Hall of the Yakima County Department of Emergency Management said no one was injured in the slide, which reportedly pushed big mounds of earth and chunks of broken pavement into the river, effectively damming it. That, in turn, resulted in the evacuation of dozens of nearby residents as the river overflowed its banks.
"The water is not backing up. It has rediverted over the Nile River Road and is taking its own course around the slide," Robert Cunningham, a U.S. Bureau of Reclamation foreman, told the Herald-Republic.