North of Houston we like Rayford Crossing in Spring Texas. Depends on what type of park you're looking for. Rayford Crossing is a nice commercial park with paved sites and lots of amenities. Cagle Recreation area at New Waverly exit off I-45 has full hookups and gets good reviews.
We use www.woodalls.com to locate campgrounds and then check them on www.rvparkreviews.com before we go.
www.recreation.gov is also a good place to find reasonably priced camping. Again, check them on www.rvparkreviews before going. Enjoy your travels!
