For my fellow Houstonians thirsty for some outdoors!
1. Mountain Biking: Visit the GHORBA website for all the Mountain Bike trails in and around Houston (http://www.ghorba.org/).
2. Rock Climbing: For indoor climbing you can go to Texas Rock Gym located on the west side of the town (http://www.texasrockgym.com/). If you would like to hit the real rocks, there is not much you can do around houston. The closest place you can find is Remiers Ranch which is just west of austin.
Reimers Ranch: Travis county Milton Reimers Ranch is about 30 miles southwest of Austin. From Houston take i-10 west to Highway 71 all the way to west of Austin through the town of Bee Cave and turn left onto FM 3238 (Hamilton Pool Road). Drive around 12 miles to the park entrance which is on your ride. The hours of operation are from 8 AM to dusk. Entrance fee is $10.00 per vehicle.
There are about 100+ routes that ranges from 5.6 to 5.14. Keep in mind that these are sport climbing routes, so you better bring your own gear. A 40M rope and a set of 6 quickdraws will be enough for every route. The Climbing 
walls parallel a section of the Pedernales river, so make sure you jump in the water after some hardcore climbing. A good guide that covers not only Reimers information but also most of the Central Texas Climbing is “Austin Rock”.
