BLM land just outside the south (main) entrance to Black Canyon National Park. Road can be rough, especially slippery mud after rain. Many dispersed sites with cleared space and fire rings along the road, which goes for miles. Reserved campsites within the National Park can be difficult to get … there's no shortage of sites here, just outside. There's a small store at the junction of the Park access road with US 50, selling firewood, ice, and necessities. Montrose is a short 15 miles away for more substantial needs (gasoline, repairs, shopping).
These backcountry sites are a challenge to get to but they are definitely worth it when you get there. You pick your site basically wherever you want and anywhere you go you will be able to hear and see the river.
About 10 spots off the main road in to Black Canyon.