We more or less followed https://www.alltrails.com/en-gb/trail/us/north-carolina/jacob-branch-loop--2 but the problem with the All Trails route is that it starts at a camp ground which does not make a lot of sense for those not camping.
I started my GPS on the side of the bridge where I ended, but apparent it did not pick up until after I crossed the bridge, so I guess that is not the official start of the route.
The route is not super tricky, but you probably aren't going to set a super fast time your first time out because the route is a loop of many of the trails. It is a nice selection of the buffet of routes South Mountains State Park has to offer. There is nothing too strenuous or challenging, but there are definitely some sharp rocks. This is not a hike to take young children on. However, there are certainly sections at the beginning and end where children would be very comfortable. There is a fair amount of dirt road, also a reasonable section of paved path, and some true hiking trail. It seems like it would be a fun race route with equipment selection being probably a bigger component of the winner than in a lot of 15k courses. Feels the the type of course that would be great for gravel cycling. Road bike, gravel bike, or mountain bike? I don't know if bikes are allowed on all of the trails though. Certainly horses are allowed on much of it, so watch out for horse poop! Except at the end, there is no water along the trail, so make sure you bring some.
Be aware that T-Mobile and Verizon are both not likely to have cell signal the entire time.