Bison were introduced to northern Arizona in the early 1900s, in a scheme to cross-breed with cattle to produce "beefalo." The bison no longer look like cattle but still have about 10 percent cattle in their genes. They eventually migrated into the Grand Canyon National Park, where the current population is estimated at 400-600. This small herd of about 15 ran across the dirt road ahead of my truck as I drove out from Point Sublime, pounding up the hillside through the Ponderosa pine forest.