CHINLE, Ariz.-Even with modern technology, it's nearly impossible to find the homemade boxing gym identified by a tattered wooden sign that reads, "Damon-Bahe Boxing Gym."

In and around this small town on the Navajo Reservation, house numbers rarely exist. And Google Maps can't quite explain that, off Indian Route 7, less than a quarter mile west of the Chevron gas station, there's a dirt road that, after three right turns, leads to the gym and another sign, this one warning "Beware of Dog."

The modest gym, which was built on a patch o...