The Horry County Bike and Run Park (aka The Hulk) is almost all singletrack with a couple of straight doubletrack sections on the sides. Several sections in the lower parts have had poor drainage in the past. Most of these areas have been drained by ditches cut by volunteers, or relieved by bridges. Still, you should give the trail a day or so following a good rain.
On the faces of the steepest climbs, volunteers have shored up loose soil with mats or old carpeting. Sounds hokey, but it works well and prevents erosion. You'll see lots of evidence of just how hard local mountain bikers and trail runners have worked to maintain the continuity of this trail.
The pump track is the newest section. It's a couple hundred yards of jumps, tabletops and berms. You can ride it separately, or make it a part of your lap as it detours off the regular loop.
You can park right at the trailhead as shown on the map, but that involves driving out International Blvd and taking a left onto River Oaks Blvd, and then another left onto Frontage Rd B-2 just after going under the Hwy 31 bridge. A lot of locals just bike across the Grissom Parkway bridge bike path either from the YMCA parking area or their homes.
A surprisingly great trail for the area. CCORS races are held here annually. The course is competitive and challenging with several short steep climbs and technical drops mixed with twisty, flowing singletrack. Rain can be a problem as the area around the biggest climb (i.e. "The Hulk" ) can flood.
This area can be bypassed in that event. The Myrtle Beach Triathlon Club used to maintain the trail and keep it in great condition. It is currently maintained by Cape Fear Sorba. There have been recent additions including a pump track with jumps and tabletops. So, remember to pack your mountain bike for your next beach vacation in Myrtle Beach, you'll not be disappointed.