The course is a 25K (15.5 mi) loop around Lake Macbride. 50K runners would do two loops. Surface: ~1/3 park & county roads, ~1/3 crushed gravel, ~1/3 dirt and grass trails. One little climb up some rocks (may need your hands). One water crossing in rushing cold water, about 30 yards wide, possibly up to your knees. Not for the faint of heart if the water is high! The good news is you pass by the start about a mile after this if you want to change shoes. The trails are technical at times. Course record 3:34:21 for men and 4:21:41 for women for the 50K. Aid stations every five miles with sport drink, typical ultra foods, and portapotties.