Travelers who plan to use State Route 410 near the east entrance of Mount Rainier National Park should prepare for traffic delays starting Tuesday morning.

Contractor crews with the Washington State Department of Transportation will perform emergency rock-slope repair work on the hillside west of the Crystal Mountain Boulevard gate.

Both directions of traffic will alternate through a single lane for up to six weeks.

During the first two weeks of work, crews will remove loose rocks and trees from the hillside. They'll spend four weeks drilling large bolts to stabilize rocks.

WSDOT has been working in the area since mid-April when a rockslide came down onto the roadway.

While crews installed a barrier to prevent further debris from falling, a rock damaged a vehicle in early May.