We come here quite often. The road up to Red Rock Canyon is quite twisty and in parts narrow, but I have seen RV's make it just fine. My kids think the drive up is one of the highlights!
It is not uncommon to see bear, deer, long horn sheep and even moose in this area.
Once you arrive at Red Rock Canyon the actual canyon is right by the parking lot and has a bridge over the canyon that is wheelchair accessible. There are public toilets available.
There are several hikes of varying length and difficulty starting from the main car park area, some are paved and others not. You are allowed to climb down into the canyon and walk up the river, which many people do, it's allot of fun.
As you are leaving the main car park a short way down the road there is a turning to the right and here you will find an enclosed picnic / BBQ area right on the side of the creek. Our kids love this spot because it is usually deserted and they love to sit on the bank and throw pebbles into the water. Dogs are allowed on a leash.
This is a stunning place and well worth visiting.