Since I frequent Schooley's Mtn, living in town, I have noticed a few things that have changed in the past couple years that the maps don't show.
-The Green "Boulder Gorge" trail used to head down a steep drop, cross a gravel driveway (which leads to a house) and over Electric Brook and back up into the park along the far bank of the stream. Now (since at least the time of Irene I would guess since that's when I noticed) it has been terminated at the gravel driveway and there is a sign saying the rest of the trail is closed. Maybe it got washed away? maybe it was considered unsafe (there was a sort of ledge at one point you had to walk on to get around a rocky area on the trail that jutted out into the stream a bit, maybe that was considered unsafe. Maybe there were property disputes with the residents who live back there? who knows.
-The "Quarry Stone" trail indicated on the map on the county park system site is marked as a Yellow blazed trail. This has changed and there is only Yellow blazings where the Grand Loop trail goes on the map. The Quarry Stone route is now (as of at least late spring 2013) blazed PINK. The trail has always been there, just never had a blaze. It goes between a bench area along the Yellow Grand Loop trail to the rocky overlook at the Highlands/Patriots Path (teal diamond/white)
-It seems to be unclear whether they want you to be able to cross George Lake on the floating bridge or not, they keep moving it. They're renovating the boathouse on the lake (maybe they're going to bring back the paddleboats?) A couple years ago they had to completely drain and dredge the lake because fertilizer runoff caused toxic red algae to grow in it. The lake has been refilled for over a year and a half or so now but I'm not sure whether they allow swimming.
-If you take either the Bee Line trail or PP/Highlands, you'll end up crossing Fairmount Road at a parking area for the Columbia Trail/Gillette Trail. Gillette Trail is a short spur trail that crosses Columbia Trail and the Raritan, eventually taking you to the parking area along Mill Road (513) in the valley. For at least the area between Columbia Trail and Mill Road it is partially blazed with blue PP logos as it's considered a spur route of Patriots Path.
Once you get to Columbia Trail from Gillette Trail coming from Schooley's Mtn, left is PP, right is Highlands. As with many places in the general area PP and Highlands split and rejoin each other before PP ends in Stephens State Park (which is actually in Morris County)
Just some things to notice if you haven't been there in a while or never been there and are relying on the outdated maps.