"The Natural Horse" was based upon Jackson's studies from 1982 until 1986 of the Mustang in its natural environment in the Great Basin of the western United States. Jackson discovered that not only did wild horses live longer than domestic horses, but they also suffered none of the hoof maladies that plague those kept in 'captivity', notably navicular syndrome and laminitis. Following his research, he began experimenting on the hooves of domestic horses to find an effective way to trim their feet and allow them to remain barefoot and strong. In 1990 he stopped all shoeing of horses and instead began to advocate for the wild-horse trim. He believed that even horses with severe hoof conditions deemed incurable by veterinarians and farriers could, over time, be restored to good health through barefoot trimming and natural horse care (i.e., naturalization of the diet and boarding situation).