Visited my in-laws at their former winter HQ in a very nice Yuma, AZ RV park. The management insisted on a 55- and- older clientele and advertised a fairly steep overnight transient  fee  on their billboard out front.   Seasonal and monthly rates were quite reasonable IIRC. The idea was to keep the riffraff out. The only pop-top was a Eurovan which a Canadian couple placed in front of their park model unit for daily driving. It was illegal to actually sleep in a vehicle parked in a driveway.
The customer base is often  word-of-mouth and people often plan to return year after year. Make good friends with fellow RVers-you may need references for the cleaner locations.

My parents RV'd into retirement. They mentioned that older RVs are not readily welcomed in a lot of the nicer places.
George. 83.5 Westy parked in the driveway. Grand Rapids MI
No actual personal RV experience.

> Wasn't there a time when you had to
> pitch a tent
> ( just to get in the tent spaces? )
> with an RV er' VW Camperbus?
> & then have to sneak into your poptop to sleep?
> I guess their getting a little better :o)
>