A great loop around the perimeter of OP. Features a bit of everything found in the CenTex area with options for easier or much harder sections if desired. You'll find well worn singletrack that is smooth, twisty rock and root sections and even an area or two with options for much harder technical descents. Probably best done Clockwise as this sets you up well to climb out of the low area in the SE corner of the park. Done CC, I'd take the shorter loop option and not drop down low.
Depending on the skill level of the kids, a lot of this trail isn't too bad. It is noticeably more difficult than the Blue Loop
At the NE corner of the park, near the Power Tower, there are two route options.
Option 1 (Shown Here): This continues the nice, moderate terrain by following singletrack south on the WEST side of the paved Old Tower Climb Trail
. Simply pick up the singletrack south of the Tower and continue South until you reach the southern park boundary.
OPTION 2: Is the more difficult option that will drop you down a very steep hill to the lower part of the park near the Leon Creek Greenway
. When you reach the Power Tower station, you cross over the paved path to the east side and look for trails branching east off the pavement. As soon as you are are this you turn NORTH and continue north. The more north you travel the less steep the trail options are. Be careful if you head east or SE as the hill becomes a cliff. There are some impressive trails back there! As you con't NE you'll descend into the lower creek bed area and turn SOUTH, following trails along the creek bed. Near the SE corner of the park, you'll either follow a trail back up to the SW that will return you to upper OP or you'll go so far South you'll hit the Leon Creek Greenway
at a bridge crossing over the creek bed. Look for the spilt in the paved trail with signs taking up back up to OP. The loop trail will branch off this to the west at some point.