Ideas for inexpensive outdoor wedding sites in Dallas, TX area?

I'm just starting to plan my wedding and it's a year and a half away so I have plenty of time but I want to start scouting out reception venues. I would love some place outdoors b/c I'm looking for a very relaxed natural feel while maintaining some elegance. I don't live in the Dallas area so the internet is my best friend in planning. If you guys know of any beautiful but simple locations that won't cost an arm and a leg that would be awesome. Thanks!