Recommended RV campsites Utah and Arizona

[CatName]

We are planning a long road trip to the West Coast in September 2020 and booking a compact (but still bloody big) RV for part of it. I wonder if any of you have recommendations for RV campsites in or near any of these places please?

Zion
Bryce Canyon
Monument Valley (probably staying at Mexican Hat)
Flagstaff
Needles

I think all the areas/parks you mention have web sites with camping advice. Lots of advice on Lonely Planet forums too. Book early would be my advice. Bryce is a day trip really.

Thanks Bubbles. I just wondered if people had personal recommendations. Bryce will be a pit stop for us - it's going to be a long trip so we are trying to pace ourselves with the amount of driving