Depending on your strengths or what you are looking for on your run, consider the direction you go. Counterclockwise has a steep initial descent with long climbs (same direction as described above). Clockwise offers probably the fastest route because of the long downhills are over runnable terrain, but the climb would be at 15-20% grade.
Accessible from McKenna Trail
and Painter Rock Trail
(via a connector), the North Loop Trail
is a rugged 5 mile loop with 1000 feet of climbing. There are three elements to this trail: jaggers, rocks/boulders, runs. Going counterclockwise, the trail begins with a gentle descent, before turning straight down the mountainside at ~15-20% for a quarter mile, and then easing up again. The beginning section of trail, at roughly 2800 feet, is covered in knee-high grasses, similar to McKenna Trail
. As you descend the trail, the grasses thin and vanish, before around 2200 feet, jaggers (briars) appear and thicken. This makes the trail a bit tougher to run because the jaggers are large enough to cut up your legs. You may note a run crossing that cuts the trail diagonally. You'll cross this run later, when it is much larger and rushing downhill.
Around the first mile, the trail takes a significant turn left (south), but there appears to be other options. Follow the yellow blazes. Very shortly after this turn, the trail makes another hard right, which is miss-able. Small logs and sticks are dragged across the trail to mark the turn. If you stay straight the trail becomes noticeably less "maintained" and you'll not see any yellow blazes.
It is very shortly after these series of turns that you'll come to a brief section with boulders on either side of the trail and look like monuments. It's a nice reprieve from the jaggers and monotony of the trail.
Once at the bottom of the mountain, the trail slowly begins rising. You'll cross two streams at this point. The first stream you'll have crossed earlier, and has grown as it picks up more water. The other stream originates within the loop. Roaring Run Natural Area contains several natural springs. Note the clarity of the water.
The final big turn marks the start of the 1000 foot climb. Unlike the descent, it is less steep and can be run in many of the sections. There is a connector trail to take you to Painter Rock Trail
about mid-way up the climb.
You'll arrive back at the loop start with McKenna Trail
to the right.