Steuart began riding as a child in the hunt field, in pony races, and at local shows. He was introduced to eventing through Pony Club and learned the fundamentals of dressage as a teenager from his inspiration and mentor, Ellen Shepherd, one of the first US importers and breeders of European warmbloods. 

In high school Steuart evented through Preliminary on his Thoroughbred mare, Hurricane Hannah, a California-bred race horse who came to him straight from the vet clinic after having a chip removed from her ankle.

Erin has had a fascination with horses for as long as she can remember. Growing up horseless but next door to a ranch in Colorado encouraged her to finally get into the horse world for good as a college student. She dreamed of veterinary school from about the age of 4 onwards, but high school chemistry scared her into pursuing a degree in Political Science from the University of Colorado instead. After volunteering at Colorado Horse Rescue for several months, she decided to try again for her childhood dream and enrolled in Colorado State University's Equine Science program in 1996. After finishing her second bachelor's degree there, Erin entered into a graduate program in Equine Nutrition instead of going to vet school.