Ohhh. That sounds so fun.
Texas isn't really mountainous, but we have beautiful state parks. Caprock Canyon is in north Texas. That's still quite a distance from you, but maybe you would like to check it out?
TPWD: Caprock Canyons State Park and Trailway
Even farther:
When I was about 8 years old my family camped in the mountains in Colorado. I will have to ask my parents where exactly we were because that was a gorgeous place.
And a friend told me Wyoming is amazing. He really loved it there.