If you are planning on staying several days at TX state parks on your trip & depending on number of people in your group, it may pay you to purchase a state park pass( $70). It covers the daily entrance fees which are per person. It can pay for itself pretty quickly (sometimes); do the math. Plus it gives you two nighs camping fees at half price. Each state parks daily fees are different, usually $3-7 per person per day. You can see the fees at each park at the state park website. Just Google Texas state parks & then look at each park's info. You can purchase a pass at any state park when you arrive, but ask about it before you check in. Enjoy your trip!