Hidden Cove Park used to be run by the city of The Colony. It had the feel of a state park because I think it used to be Lewisville Lake State Park (at least that is what it is listed as on some maps). However, I really don't know for sure about its past as a state park. We day-hiked/geocached there several times some years ago and also backpacked to one of the primitive camp sites on the lake (approx. 2 mile walk from the trail head) which was great.
The city of The Colony has since turned over management of the park to a private company. I think it was at that time that they took down the old website that had quite a bit of info. Here is the current website:
http://www.marinequest.net/hiddencove/ Here is the link to the boat rental store:
http://www.hiddencovepark.com/
The new management company is apparently doing a lot of renovations. At the beginning of that process, there was a sign at the trailhead showing the new trails that were to be added. The website talks about a new marina. However, we have not been there since it was turned over to the private management company so I cannot confirm any of that.
Let us know what you find out. I can't speak to the
RV type of camping, since it is not our thing, but I thought the park used to be very nice. There were multiple amenities and the restrooms/showers were clean, etc.