The "Loop" consists of the C&O Canal, and 3 connecting trails within the forest. I've hiked it several times. My favorite route is to park at the Paw Paw lot on the C&O canal, hike about 2 miles and camp there. After a few miles down the towpath the next morning you enter the forest on Long Pond Trail. Follow that North until you reach Deep Run/Big Run trail. Follow that South until it ends and connect with Log Roll Trail. Follow that back to the Canal towpath, and hike back to the Paw Paw parking lot. Easy enough.
Follow this link for a good online map that will give you an idea of the "loop"
Water in April is no issue. In fact, you cross a stream several times so be prepared for wet feet.
I can post some pics of the forest and trail if anyone is interested.