If I understand correctly, this is not going to be a full blown RV park, but a place for secure overnight parking in an area between two destinations that are 500 miles apart. Not a destination, not a place that will provide washrooms and individual sewer dumps. Simply a place that has electricity of some description, possibly water to each of a small number of parking place/sites, and one sewer dump. Probably be the old classic dump if there is one-the submerged 55 gallon drum with holes in it.
It would be a step above dry camping at a Pemex for most people and would definitely beat the 500 mile drive between San Carlos and Mazatlan.