"It is probably too late book reservations anywhere so I wanted to get a feel for some of the best NFS, BLM or other boondock spots."
I've been RV'ing around the western states for 15 yrs and haven't ever made a campground reservation. (I stay out of Ca)
Pick an area near any National Forest, stop and get a motor vehicle use map from the ranger station and pick your spot. You could spend the next 10 yrs dispersed camping in the high country from NM to Canada and never stay in the same spot twice.
Taylor Park is a great spot if you're bringing your ATV along. Otherwise its a crowded, noisy spot with 100's of ATV's running past your door all day. There are 1000's of Taylor Park like spots, that you can have all to yourself, it just takes a little exploring. In the middle of the summer heat, look for areas above 7,000 ft elev.