I have never been to the actual site but I drive by the area all the time traveling between San Diego and Phoenix. Its just off highway 85, maybe 45 minutes from Phoenix and 30 north of Gila Bend. Not much out there other than a jail and a landfill. I don't think Spring Mountain got much traction and I'd be surprised if that site had its operating costs sorted out. I'd look at some of their other, more established sites.
Here is a link: http://waterskiarizona.com/index.php
Susan, the agent, is pretty responsive and should be able to give you the scoop. I think she has a place at Lakeside which is just south of Spring Mountain.