From Mount Rainier NP:
The Washington State Department of Transportation has announced they expect to open State Routes 123/410 over Cayuse Pass within Mount Rainier National Park on Friday, May 15 at noon. The pass had been scheduled to open on Tuesday, May 12, however a late season snowstorm delayed the opening.
Once this roadway is open, the public will be able to travel from the southern boundary of Mount Rainier National Park via State Route 12 to State Route 123 north over Cayuse Pass to State Route 410 to the park’s north boundary near Crystal Mountain. WSDOT anticipates State Route 410 east from Chinook Pass to Yakima will open by the Memorial Day weekend, barring any snow removal delays.