The race web page is http://altisendurance.com/events/brush-tunnel-marathon-and-half-marathon
Local time: 3:53 AM
The course consists of 1.31 miles of the great crushed stone surfaced Great Allegheny Passage. Marathon runners run 10 out-and-backs of the course, and the half marathon runners run five out-and-backs of the course. Half marathon runners will run through the 914 foot long Brush Tunnel 10 times, and the marathon runners will run through the tunnel 20 times. The course is not flat, but the elevation gain and loss is all gradual. The half marathon has 1425 feet of gain and loss, and the marathon has 2850 feet of gain and loss. Feel free to enjoy the views while running the race!
If you like tunnels, this is the marathon course for you!