I was planning to just take a peek at St. Edwards Park when I drove to swim downtown on Saturday. I parked the car right outside the park entrance at 1.30pm and started my investigation. That investigation turned out to be a 8.5 miles hike from St. Edwards Park to West Bull Creek Preserve, which is located at the junction of 2222 and 183.

From St Edwards Park entrance, follow the hilll trail until you reach the gate to Balcone Canyondland Preserve.  You can find GPS info from the http://www.texashiking.com/Locations/ShowLocation.aspx?LocationID=1666.

Get pass the gate and the 2.5 miles (something like that) trail that led  to West Bull Creek Preserve is very well marked. First you will cross the street of some neighourhood, then you will see a giant water tank  before you start descending. There are only 2-3 forks on the way to the parking lot of west Bull Creek preserve. Whenever there is a fork, just stay on the left.

When you reach the entrace of the preserve, you will find a map which shows the trail and how it winds back to St. Edwards Park. There is also another trail in the preserve that led you to the creek (Bull Creek, I presume?). It's quite short... may be 1.5 miles return.

On your way back, stay on the left track whenever there is a fork. It took me a solid hour to walk back to my car from the entrance of West Bull Creek Preserve.