Brett,
According to MapQuest, it's over 700 miles and 12 plus hours to Gaudalupe Mountains National Park. That distance in itself kills two days in travel time. I get the notion that you're looking for some rugged terrain to backpack. I would head northeast to the Ouachita Mountains of Arkansas. Some would call them hills with elevations of only about 2000 feet. They are only 8 to 8 1/2 hours away (you could still get in some hiking time on arrival day). And in springtime with the dogwoods and wildflowers in bloom, it would be a most excellent adventure.
Wingman has posted a link to the Eagle Rock Loop in the Ouachitas (under the Hennessey Hammock thread). This is a very scenic hike and will get the juices flowing with some step uphills. Just my 2 cents.
