FUN TRIP!
My 11 and 15 year old went also and they had a great time. We went back the following day to hike Red Rock (Ice Box Canyon trail-- great hike!).
We left on the Scooters (149cc) around 8:30am and were back by 11:30am. The 3 hour tour consists of a few miles of suburban roads followed by a drive into Red Rock Canyon on a road where you drive in the bike lane IF there are cars approaching behind you. The guides do a good job of blocking off traffic to keep the group safe.
The total trip was about 25 or 26 miles. There are many twists and turns, uphills and downhills in the park, which are perfect for this type of scooter. On the open stretches, you'll get up to about 40-45 mph. As everyone mentions, there are 4 stops: one at the visitor center for restroom break (they gave us about 20 minutes there). The first stop after the visitor center (I think it's called Calico) is the best one by far...get out and go up the rock trail for great views of the Red Rocks. Again, about 20 minutes. The next two stops were nothing more than a quick photo opportunity. The highlight is cruising through such a serene and beautiful park in an open air scooter type thing. I have a scooter at home, and this park is truly the perfect setting for a ride!!