Head out the far end of the parking lot and go straight past the trail map sign. In about 100 yards you'll take a left onto the trail. If you go straight here you'll do the loop in reverse.
In 1.9 miles you'll see Flagline Trail entering from the left. To truly make this a "loop" stay straight to continue on to Swampy Shelter in another .1 mile. Go straight past the shelter where you'll head down a fast section of trail before some tighter singletrack in the woods.
There is a short, technical rocky creek crossing before you climb up some more curvy singletrack towards the intersection with Swede Ridge Loop at around 2.5 miles.
Continue straight past this intersection and you'll start climbing again before reaching the next intersection with Swede Ridge Loop at 3.2 miles. After a little more climbing, you'll hit the top just as you reach a doubletrack trail that makes for a fun and fast descent back to the parking area.