The Ptarmigans and their P trips, by Harvey Manning. Their Picket/Chilliwack trip was also rather impressive.
Interesting that more than 70 years later, the Ptarmigan Traverse as per original party is very likely un-repeated.
I like to go out to the the middle from Cascade Pass, and then return the same way. Avoids the car shuttle and you get to spend the whole time up high. The Dome area is great and worth it's own trip as well.
However you do it, enjoy!