Check out the Ruby Mountains / Lamoille Canyon SE of Elko, NV. NFS campgrounds in the spectacular canyon. You access the canyon from the NW side of the range. Could be very busy. Don't know if they do reservations. There's also Ruby Lake Marsh National Wildlife Reguge on the SE side of the range. Ruby Marsh campground is located there. It's very small.
You mentioned the North Rim of the Grand Canyon. Toroweap is accessed by 60 miles of dirt/sand and gives you access to one of the narrowest parts of the canyon above Lava Falls, 2,800ft straight down. We could hear people talking on the rafts as they approached Lava Falls. Now days, you may need a permit, although I'm not certain. Camping is allowed. 18 years ago in July there was hardly anyone in there, camping was free and we never saw a ranger. I believe those days are gone. Well worth the drive, as long as it's not wet.
In Utah, The "Little Grand Canyon" or San Rafael Swell. Remote but spectacular scenery. Campground with pit toilet but no water or other amenities. Went through there in mid September and no one was there. Of course, that was then and this is now. The overlanding thing has exploded, add in the pandemic factor and finding lonesome places is more challenging.
Edited by TGK, 17 June 2021 - 03:09 AM.