Best puppy behavior is recommended (though not enforced) as you enter through the pay-by-honor snack bar. It only takes one or two snuffs of sharp cactuses to convince your pet he should stay on the trail. The walk is wonderful, easily two hours past a symphony of Arizona history, babbling brooks and traveling sculpture. You have to factor in time for bops on the head for your kids who may insist on frightening lopes along the edge of a crevasse, and to scrub off the sticky spittle of your own sweat and dried dog drool. But you, and your hyper hound, may never be as happy anywhere as you can be, for a day, at Boyce.