We just camped at Umatilla Forks 6/12-14/2018 for the first time and loved it. I want to go back for sure. My family wasn't so sure about the more primitive aspect of the site since all it has is a couple septic restrooms and a water station but it was more than enough. we chose site #3 at the farthest north edge of the campground closest to the river fork and while it was really nice and secluded, i would choose #5 or #6 as they are more spacious and shaded spots and have the best river access. The water was freezing cold but we all jumped in to wash off a couple days of "roughin' it" and warmed up in the 75F sun. It's really not that far from civilization but it is far enough out of the way that we were 1 of 2 groups who stayed (they chose the farthest site at the other end) and saw one other drive-by. fantastic getaway that's not TOO far away.
Amenities: Septic restroom w/ 1-ply TP, and water station. you will have to gather your own wood for fire or bring your own. There was lots of dead fall and forestry downed trees to harvest wood from.