I set out to complete this loop as a 50k including the County Line Trail and District Line Trail as a circumnavigation of the Cranberry Wilderness but those trails were overgrown and only navigable via GPS according to trailhead signs. So the route was shortened to follow Middle Fork Trail and have access to water. This is a remote area and the being wilderness is not maintained to the same trail standards as more heavily traveled places. GPS highly recommended!
It was a beautiful, slightly cool start. I ran this solo, clockwise, starting at the eastern trailhead off Highland Scenic Highway. The trail follows a gentle downhill single track on the North Fork Trail, eventually meeting the North Fork of the Cranberry River. This leads to a gated gravel road the Cranberry River for a few miles until you make a right turn on Birchlog Trail - a steady climb to the ridge before jogging left along the North South Trail and then right on Little Fork Trail which drops over the other side down to the next valley. This is area overgrown in spots and GPS is very helpful. Probably would be easier to follow late fall and early spring before getting overgrown. Dropping down the north side the trail meets Middle Fork Trail running along the valley and following a stream the whole way so it's easy to get water and this is where I refilled. This connects back to North Fork trail and a short return to the trail head.