This is a simple hike and bike trail through the Round Rock West neighborhood. It's a straight shot almost literally since it follows a utility right of way. Still, it's a bit nicer than walking on the street.
This park is straight north of County 172 (mismarked on the map above) Park on Tejas, the cross street. This is just a strip of land behind houses but it is fairly wide and ends at a loop near a creek. Took half an hour for us to hike it so decent length for a neighborhood strip of land. On our way to this park we accidently found the "Round Rock West PARK" which is a different park not includied on this page which took us 15 minutes to hike (it is a few blocks east). Worth checking out that path and walk past the loop as there is a waterfall in the back field.