This is also known as American Springs Dispersed Camping. We stayed in site fairly close to the entrance and off to the right on the East spur for 6 days in a 36’ motorhome and Cherokee Trailhawk. All of the sites are very well spaced, most being a hundred to several hundred yards apart. Ours was fairly close to the highway, but it was really only noticeable during"rush hour". Only a few other campers while we were here, and most only stayed a day or two. The interior roads are dirt and get pretty rough the further in you go, with some fairly large rocks and deep ruts, some 1’ to 1.5’ deep(see photos). Parts of the ENE spur gets pretty narrow in spots, but we did a small trailer or two back that far. American Springs road, heading off to the NNE, is in a little better shape, with only 2 or 3 bad sections, similar to those on the East and ENE spurs, until about 1.25 miles in, then it gets very rough and I wouldn’t recommend proceeding with anything other than a true 4x4 or OHV, but there are a number of secluded campsites back in there. There are a number of trails/dirt roads in the immediate area to hike, some with nice views of the valley and surrounding mountains. AT&T coverage was fair, with 2 Bars of LTE service and speeds up to 2 MB/s. There are quite a few trees, but we did manage to get DISH coverage to all three western satellites at our site through a gap between a couple of trees. We were also able to get about 50 OTA channels with our fixed omni antenna.
Regarding access to the area from the East of Los Alamos, be aware GPS will route you through Los Alamos onto NM 501, which goes through part of LANL and you have to go through security check points and your vehicle(s) are subject to search. If you have any firearms, you will not be allowed to go through the lab. So, if you have weapons or don’t want to be searched, the alternative is to take West Jemez Road/NM 4 through White Rock instead and save yourself a trip all the way up to Los Alamos, all the way back down, and then back up to the dispersed area.