I stayed there with a 44 foot plus tow vehicle.

Yes! We have a 40’ and there are several spots that can accommodate.

Plenty, that's what we have and we stop there alot.

Yes, the spots are very spacious.

Yes, there are. The best advice would be to go to their website (under Maricopa County Regional Parks) and check out their campsites. They show photos and dimensions of the campsites. You can then reserve the site that best fits your needs.

Yes there are, but you have to unhook.

Sites are very generous at Usery and navigation within the campground is also very easy. You should have plenty to choose from.

Sorry, I don’t know about a rig that big. When reserving at a new-to-me campground, I always check every site I’m inclined to reserve site details, specifically, site length

From what I can recall, there should be plenty of spots for you to fit In. We have a 35 ft 5th wheel, a long bed king cab truck and an SUV and we were able to fit all of that in one of their "pull off" sites on the outer perimeter.

I would say yes, we had our 34ft trailer and tow vehicle in one no problem. The sites are very spacious and several had large motorhomes in them w/ vehicles also. Really nice park, beautiful scenery, convenient to Phoenix.

Depends on what you mean by 'many' but in the satellite image of the park there seems to be quite a few with large rigs in them. The site we had (29?) was definitely spacious for our 50' of vehicles plus off-loading the sidecar. The reservations system does include info on site width and length with some pictures so hopefully that can help you figure out your geometry. Happy travels!