Was in Scottsdale for a conference looking for some excitement. Perused the T/A listings of ATV tours and found Desert Monsters offering a sunset tour through the desert. We jumped on it and signed up. It's about a 30 minute drive from Scottsdale into the Tonto National Forest (really more desert than forest). You meet about a half a mile in at the general parking area and look for the Desert Monsters truck and ATV's.
We were greeted by Mike, one of the nicest, most knowledgeable guys you'll ever meet. It seems like you can have probably up to 8 to 10 ATV's going on the tour, but we lucked out as we were the only ones to sign up for that time slot (it was on a Monday and pretty chilly - late February). What we got was an awesome high speed personal tour spanning more than 30 miles. We told Mike we wanted to go fast and he did not disappoint!
Mike was more than happy to stop and take pictures, answer questions about the area, provide water and snacks and let us switch drivers. Make sure to dress appropriately! You're going to the desert and at sundown it will be 10 to 30 degrees colder than in the city. They supply helmets, bandanas and all the gear you need. Thankfully, Mike even had extra coats to ensure we were warm enough, but I wouldn't count on that if you're in a large group.
The machines are well maintained and you'll have a blast criss-crossing all kinds of terrain over about 2 and a half hours. The scenery is beautiful and just stunning at nightfall. We've done several ATV tours and this in one of the best!