Hot Springs
Those sound like great places. I usually go up to Baker hot springs. It's traditionaly been a clothing optional spot but the camp areas in the park around there are pretty popular during the summer months. The last 4 or 5 times I have been up there it's already been occupied by clothed bathers and I'm usually not up to the task of arguing the point with them.
Around here, Bagby is the first choice of a lot of people.....used to be a great place.......until it got to be first choice with a lot of people. We always liked McCready, past Eugene,OR....by Oakridge.
If you're going as far as Eugene, I'd definitely include Cougar Hot Springs - beautiful settiing and easy to get to. (aka Terwilliger HS)
I was able to visit both Jerry Johnson and Skinnydipper on a road trip this month, and loved them both! My traveling companion and I had Skinnydipper all to ourselves on the day that we visited.
I'd like to go back to Jerry Johnson sometime when the water levels are lower. The waterfall pools were still submerged in the river but they looked like an amazing setting for later in the year.