This is one of three ITT's promoted by Tennessee Gravel. www.tennesseegravel.com. They have the Three Rivers ITT series and I highly recommend it. The sense of accomplishment is off the charts. Then at the end of the year they have an awards party and dinner, great fun...and you get to see, meet, catch up with the other lunatics who do this stuff! This is the hardest of the bunch, in my opinion. A demanding day that can and usually is impacted by recent weather in places, though seldom throughout the course. The file has two problems with navigation. 1st is between miles 11 and 12, both GPS units got confused here. There are 3 options, stay to the left, going straight. The next will be a direction to turn right onto Big Frog rd, there is no turn. It will tell you that you are off course, but continue straight another hundred yards or so, then make a nearly 180 degree turn to the right. It will be telling you you are "off course" you're not. Follow that a quarter mile or so then turn left onto Big Frog (Hell) and start looking for that Spring Pipe for water! There are at least three opportunities for water replenishment; 1. 26-28 miles there is a spring pipe on the right. Easy to see. 2. 41-44 miles you'll hit Mulberry Gap, they have bathrooms and sinks or a water spigot for your use. If you want to report your ride to Tennessee Gravel, you will need a picture of yourself while there. 3. Spring Pipe on the right, just as you enter Big Frog (Hell) for the last time at 71-74 miles. This is a great and demanding day on the bike, more imposing than the mileage indicates! Be safe, enjoy. This would be a good on a light hardtail (maybe better) as on a gravel bike with some larger tires. I rode it on Pirelli Gravel M's - 45's. They did fine, don't think I'd do it on less.