Walnut creek is about 200 yards south of the Yager ln light on N Lamar before you get to Parmer. It's the park that has all of the softball fields. It's a great place. It has both a BMX and a mountain bike side. Here is a google link.
Awesome link. I've lived south of the river at a couple of points, but I never explored the area.
Well, it's been a while and I'm not in near as good of shape as last year, but if you ever want a tour of that place let me know. I'd say on a scale of 1-5 it's all over the place. The BMX side is 2-2.5. But the M/B side can go from 1 to 5 depending on what part of the park you are on. The parts I ride are usually the BMX side for a warm up and then hit the east side for the trail. If I have enough in me I'll hit up the west side. Most of these trails are 3s and under. My 10 year old rides it with me. He walks some of it, but rides most.
It's a lot of fun and good for a couple of hours of riding.
If you are looking to get out of Austin and do some mountain biking, check out Bluff Creek Ranch in Warda (just outside of La Grange). The trails are in good condition and I'm usually toast after 2 loops.
It isn't too technical, but you can get a good flow going & there is one tough climb.