Does it have an RV sanitation dump station?

No RV dump

Here is a website with a list of RV dump stations in California. http://www.californiarestareas.com/california-rv-dump-stations.html

I went through there a few months ago and as I remember it does have a dump station to accommodate RV travelers.

It has a large space for RVs, trucks & buses, so it is possible there is one.

I'd say no, but try and call them to make sure.

Doubt it