RZR Camping near Mammoth Mtn?

We are looking to camp with a 40′ motor home and our 4 seater RZR. We have been told that Glass Creek Campground is a good spot but to me it looks to be quite far from the town of Mammoth?

Anyone here familiar with camping and riding there?

We are looking for trails with lots of creeks and shade to check out? Are there other areas where we can camp with RZR friendly trails closer to the town of Mammoth?

Opinions appreciated!
Thanks.