The only native palm trees in Arizona are tucked away in a narrow, rugged canyon in Kofa National Wildlife Refuge. These unique plants are probably the descendants of palms growing in the region during the last periods of North American glaciation. Some botanist theorize that the trees gradually spread into these canyons and other protected niches as the climate warmed to desert conditions. Other researchers had suggested that the trees may have been spread from other palm groves by birds or coyotes carrying seeds in their digestive tract.
The only native palm trees in Arizona are located in Palm Canyon on the Kofa National Wildlife Refuge. In Palm Canyon, the trees are able to survive in the narrow canyon where direct sunshine is limited to only a few hours each day and the little rain each year is funneled directly through the canyon to the growing trees. The survival of these trees is directly dependent on the microclimate in this protected canyon. A massive fire in 1953 roared through the canyon. You can still see charred black on the trucks of the still growing adult trees.