Palo Duro Canyon is an interesting place, short drive from town.
http://www.tpwd.state.tx.us/spdest/f...palo_duro/#sch
If its a warm day and the winds' blowing just right you'll find out where the 72oz steaks come from. Amarillo is the feedlot and beef processing capital of Texas. Your nose will alert you to this. Could be a good day for a visit to the canyon.
Enjoy!