This is a big-bike friendly route from Exit 42 on I-90 (Tinkham Rd) over Snoqualmie, Stampede, Tacoma Passes. Near Windy Gap and Pyramid Peak and the Naches Trail. I’d say it’s best for advanced beginners and above. There is a rocky climb from the south end of the Stampede Loop up to the high shelf roads that parallel the PCT - rd 7036. There isn’t that much loose rock. You just need to be comfortable picking a line and sticking to it. The route is 151 miles long with 30k ft of ascent/descent. There are numerous escape routes including Greenwater and FR19 to Clifdell. Enjoy.