Shelby County recently issued the following announcement.
Date: Friday, December 4, 2020
The 2020 Blood Rock 100 or 50-mile trail race will likely be the hardest 100 or 50 you have ever run. The 100 will have well over 50,000 feet of elevation change, the 50 -mile, 25,000 ft. However, the elevation gain is not what makes the race so hard. It is the terrain. Our little mountain at Oak Mountain State Park is only 700 feet tall and about 10 miles long but what it lacks in size it makes up for in brutally steep technical climbs and descents, treacherous trails, and endless miles of rocks and roots. Then again, there are also some very gentle and very runnable trails. But not many!
Original source can be found here.