The Moyle is a rare horse breed. The breed is thought to have origins in the horses bred by Mormon people in Utah during the mid-1800s, and it is believed that the Moyle horse of today was bred by Rex Moyle in the mid 20th century, incorporating Mustangs and Cleveland Bays into the lineage. DNA studies in the 1990s indicated that the Moyle horse has genetic markers suggesting some common ancestry with the Spanish Horse. Moyle horses often have small frontal skull bosses, referred to as "horns" on their foreheads, a trait seen only in a few breeds, such as the Carthusian horse of Spain. They are also noted for unusual freedom of movement in the shoulder, associated with the positioning of their forelegs a bit farther forward than other breeds.
- Dutson, Judith (2005). Storey's Illustrated Guide to 96 Horse Breeds of North America. 210 Mass MoCA Way, North Adams, MA 01247: Storey Books. pp. 181–184. ISBN 9781580176125.CS1 maint: location (link)
- Hendricks, Bonnie; Anthony A. Dent (2007). International Encyclopedia of Horse Breeds. University of Oklahoma Press. pp. 296–299. ISBN 978-0-8061-3884-8.