bigbendrvresortadventures.com is the website for the rv park in Study Butte. We stayed there and liked it just fine. It's only about 3 miles or so to the entrance of Big Bend Natl Park.
If you've never been, I would like to suggest that above and beyond the beautiful Big Bend park itself (which we loved--great scenery, not a lot of crowds), please go to Terlingua, just a few miles away. There is a little ghost town and a very unique cemetery you can wander around in--plus the Starlight Theater (now a rustic restaurant) has great food! Next to it is a little store and on the front porch there are usually "locals" you can talk to.
The high to Terlingua will lead you to Persidio and a drive that is breathtaking!
We hope to return to Big Bend soon....it is one of the favorite places we have visited. Hope you enjoy