This was a great guided mountain biking tour. They pick you up at the hotel early (0600) to avoid the heat. Provide helmets, gloves, water, snacks and really nice full suspension mountain bikes. There are a couple of trail options. We went for the bootleg canyon "basic" ride. It starts out with a slow gradual uphill, that was still difficult. We had plans to go on a bootleg canyon loop, but after several miles it was clear we weren't in the greatest shape (well, 2 out of the 4 of us), so we switched to the Hoover dam ride. We had a lot of fun, hit the teeter-totter and lot's of nice curving up/down trails. Jeff, our guide, was really patient and good.