It’s great to hear your knee replacement is going well! Access on the Upper Clackamas has always been a bit challenging but a few years ago American Whitewater, the Forest Service, and PG&E teamed up to improve access with boat ramps and parking lots for boaters. Unfortunately the boat ramp at Fish Creek was destroyed by the Riverside Fire in 2020.
Although their are boat ramps, access still involves carrying boats up and down hills so you’ll want to keep your boat light and get some help.
