The NJ1K club has great pictures of the split rock trail and associated description:
Although Boulder Pine Peak is officially trailless, there is an unmarked, yet maintained, path that leads to the summit. The easiest route to the summit begins at the parking area at Bearfort Waters. Following the Old Coal Trail, hikers will pass by hemlock groves, fern patches and former homesteads. The turn-off for the summit spur trail is marked by a sign indicating "Split Rock". The wood bridge and the lemon squeeze makes this a very cool ride.http://www.nj1k.org/mountain/?id=45
Although Boulder Pine Peak is officially trailless, there is an unmarked, yet maintained, path that leads to the summit. The easiest route to the summit begins at the parking area at Bearfort Waters. Following the Old Coal Trail, hikers will pass by hemlock groves, fern patches and former homesteads. The turn-off for the summit spur trail is marked by a sign indicating "Split Rock". The wood bridge and the lemon squeeze makes this a very cool ride.http://www.nj1k.org/mountain/?id=45