we have had children wander off in NW FL before, and, in one case, from the first call to 911 until everything our sheriff's office had was mobilized was about 20 minutes- horses, cars, foot search, helicopters, you name it...
the child, who was eight, wandered out of neighbor's garage, said he had been in the attic over the garage, looking at "magazines" with his friend, also eight, and couldn't understand what the fuss was all about, and why his mom wouldn't stop hugging him, until our sheriff, who, BTW, stands 6'9", showed up... and told him why all of this was happening! You better bet he didn't stray far from home after that!