The road is nice gravel for most of the way in, but the last 500 ft to the shore is a very bumpy dirt road so trailers might have an issue. But that road leads you to a open expanse of rocks next to the rivers edge you can camp on or drive back a bit into a sparsely wooded area. Primitive camping because it’s free, no amenities. But there is a lot of drift wood to use as fire wood and many perfect fire pits made from the rocky ground.
Spent a week here 2 summers ago, planning on another 2 this summer. Road in is pretty rough. The view and place is gorgeous though. Good cell service with AT&T. Pit toilet on the other side of the bridge.
On the SW side of the river is a great stretch of shore for tents, vans or whatever else will get past the very bumpy dirt "driveway". There's not a lot of shade, but enough to survive. It's a very scenic spot to hang out for a few days while you explore West Glacier, which is only a few miles away. I had very good reception with Cricket (AT&T). There's not a lot of privacy.
I was traveling to meet up with a group of friends in Glacier NP as a stop along my solo cross country road trip. We didn't set reservations and all the campgrounds were full, so we opted to "dirt bag" it and take advantage of some free dispersed camping by the Middle Fork Flathead River. It's a popular spot for people to do this, as well as for folks to spend a day on the river, swimming and floating etc. There are plenty of large, flat spots to camp so you can usually find a place even late in the evening. A nice location with river access, incredible night skies, easy access via 15min drive to the west side of Glacier NP (photos), flat ground, perfect for a quick camp fix! Of course, it's busy and so not very quiet or private and since it's dispersed camping, there were no facilities - but we're not picky. We took advantage of the space to play some camp games, too.
One of the most unique campsites I've ever stayed at, RIGHT in the river bed! I stayed here for 3 mights while visiting the West Glacier section of Glacier National Park, and LOVED it! Met so many awesome people and had such a great time by the river. Only downside is that the Verizon data signal isn't ideal.