700 acres has some great technical singletrack. Some obstacles on the trail are: roots, "baby-head" rocks, hills and some jumps. The North end of the trail is posted (No Trespassing Signs), so try and avoid that area unless you are feeling "lucky." The South end of the trail offers more trails and a little better riding. There are also low hanging branches and exposed cliffs so stay alert and enjoy! This area is also known to ATVs and Motorcycles so be aware. There are also several companies that are buying up a lot of this area so keep an eye out for those "No Trespassing" signs.
In San Antonio, take IH 410 South to Exit #39. Take a right onto WW White Rd. Take a left at the stop sign (onto Military Drive). Follow Military Drive West for about 2 miles and turn right onto Alsbrook Drive. There is some parking along the side of the road (but remember, it's the side of the road). Take you bike and ride further down Military Drive for a couple of hundred yards and go under the bridge to the trailhead. <br />
http://www.singletracks.com/item.php?c=1&i=1491