Outdoor Resort Palm Springs (actually in Cathedral City city limits) is a beautiful resort (
http://outdoorresort.com). Not sure if they allow Class B or C motorhomes these days.
Emerald Desert RV (
https://www.emeralddesert.com) in Palm Desert is very nice. It's near I-10 and near railroad tracks, but we were never bothered by that.
There are several other RV parks in Palm Springs or nearby, but we've never stayed in any of these.
We've never been able to find a nice RV park in or near Santa Barbara.
Bruce and Sharon