Chinook and Cayuse passes through Mount Rainier National Park to reopen this week by Callie Craighead, SeattlePI Good news for Seattle drivers looking to plan a scenic day trip over the long Memorial Day weekend: the Chinook and Cayuse passes through Mount Rainier National Park will reopen to drivers for the season this Friday. The Washington Department of Transportation (WSDOT) announced through social media Tuesday that maintenance crews were in the final stages of clearing the roadways to open in time for the holiday weekend. Both passes close each winter due to avalanche risk, and had been closed since Nov. 12.