Aetna Alaska Native Corporation maintains 2 campgrounds: Sailors Campground near the Gulkana River, and Hilltop Campground near the Copper River.
This allows camping, parking, fishing, and crossing of Ahtna lands. The cost is $30 per group/vehicle per night.
This is a super quiet out of the way campground on the river. It isn't very maintained and there are no facilities, but if you want a quiet and peaceful night by the river it's perfect. I would definitely stay again!