Mary Duke, an amateur dressage rider, has adopted and trained 16 Mustangs over the past 25 years. She adopted Slide in 2017 as a nearly unhandled 3-year-old from the Sand Wash Basin Herd Management Area in Colorado. Duke’s training philosophy for Mustangs involves a slow, methodical approach that prioritizes establishing a solid relationship and building trust before anything else.

Slide’s journey with Duke shifted towards dressage when she fell in love with his canter. They began competing in dressage shows, focusing on training and first levels. In 2024, Slide earned his second consecutive U.S. dressage Federation All Breeds Award championship from the American Mustang and Burro Association at first level. Duke believes that Slide is an ambassador for Mustangs, ponies, and the sport of dressage, showcasing the potential of these unique horses in the dressage world.