Ranger Dave must check everyone's photo ID before the trip can leave -- forget your driver's license and you don't get to go! He also inspects all the equipment for safety and leave-no-trace gear (toilets and firepans) and gives the entire group a mandatory hour-long lecture on the river. Nice guy with the very tough job of keeping an eye out for morons. About 15,000 passengers on commercial motor rafts (never do this!), plus 4,000 more on commercial oar boats (better way to go) and another 4,000 people on private trips (the best option) run this section of the Colorado River each year.