There are a series of campground along the Clackamas River outside of Estacada and Fish Creek was my favorite. I haven't been since the fires of 2020, so don't know how it fared.
There were a few yurts here as well. There is no cell service, sites are not level, the river is right there. It's perfect.
There's a trailhead that follows the river. Sit and watch the raft boats go by.