This article, cut and pasted from an online message board and several years old, sums it up nicely.
Its a little late I know but I ran across your question regarding the MOYLE horse. The horses were brought to Utah in the mid 1800s, by Porter Rockwell at the request of Brigham Young. They were brought to be used by the Mormon settlers as a working farm horse and to be used by the Pony Express. Where Porter Rockwell got the horses is not known, only that they were brought overseas by ship. But they proved their worth with incredible endurance and stamina. Porter Rockwell fell in love with this breed and bred these horses for use in the stage lines and buggy horses. After his death the horses he had bred so carefully were sold off and and crossed with other breeds. There is a record of a Pony Express company paying $250 per head of the "Mormon horses" when $25 would have bought the best horses available.
A rancher named Chris Hansen had the fortune of living near the Pony Express route and was able to trade for one of the "Mormon horses". That mare had a filly and the filly was given to his daughter. That little filly had 16 foals which became the foundation herd for Chris Hansen's sturdy ranch horses. Chris Hansen's "Mormon horses" became famous in the area for having unlimited endurance and a working ranch horse that could last one rider, all day; when most ranches had to have a working string of 5-7 horses per cowboy, per day.
When a horse breeder named Rex Moyle, Chris Hansen's grandson, was a young man he went into the Cedar Valley where the Mormons had grazed their livestock he carefully looked through hundreds of captured mustangs and he found breeding stock that had the characteristics of the ranch horses his grandfather Hansen had bred and loved so much and he began breeding MOYLE Horses. To avoid inbreeding, some outcrosses were made to Cleveland Bay horses.
These horses owe their unusual endurance and stamina to an unusual freedom of movement in the shoulders. The forelegs are place extremely forward of the ribcage which allows for greater stride and movement. The liver and spleen of these horses are larger, giving them the greater advantage of red blood cell replacement for long distance endurance. In 1961 the Moyle family began entering in endurance races placing consistently in the top 6 and winning awards for having the overall best conditioned horses at the end of the races. Their horses were often the only ones still in good enough shape to ride into town to collect the prize money.
Not all of the Moyle horses sport the frontal bony bumps but they all have the endurance of the original "Mormon Horses".
Blood samples show trace lineage to the Carthusian Andalusian and from there to some asian breeds who show some of the horses with bony bumps on their foreheads.
Brief History
Moyles are named after a family that bred them for generations. However, the family freely acknowledges that they did not originate the breed. The Mormons did that. Bringham Young was supposed to have them himself. How he discovered them, no one knows.
Mormons kept their incredibly strong and small horses to themselves with strict orders that they were never to sell their horses to unbelievers. However, according to International Encyclopedia of Horse Breeds (University of Oklahoma Press, 1995), many Mormon horses served in the short-lived Pony Express, costing 100 times more than any other horse because of their stamina.
Legend has it that the non-Mormon rancher Chris Hansen long admired the Mormons’ little horses. One day a Mormon’s mare dropped in exhaustion on Hanson’s ranch property. The custom at the time was to lend a fresh horse to the stricken rider. Hanson, sensing it was now or never, refused. But he would give a sound gelding in the place of the dying mare. The Mormon accepted and was on his way.
The mare recovered and soon foaled a filly. That filly in turn had sixteen foals. She was given to Chris Hansen’s daughter, who married into the Moyle family of Idaho. The Moyle family has been breeding them ever since. Some Cleveland Bay was added in order to keep the core herd from inbreeding. However, it is unknown if the Moyle family has continued the work and no breed registration exists.
General Description
Not all Moyle horses have frontal bosses. They do have forelegs that are positioned the furthest forward of any breed, making their strides long and smooth. They now stand about 15 hands high but can be smaller. They have long backs, handsome heads and excellent hooves. Their livers and spleens are the largest of any horse breed in the world, which may be one of the reasons why Moyles have such incredible stamina. They come in several solid colors, but mostly bay and chestnut.
Moyles excel in trail riding, ranch work and endurance riding. One Moyle named Hawk is in the Endurance Horse Hall of Fame. Another Moyle endurance horse champion was named Pretty Boy Moyle and was ridden by Bonnie Rose Sehlemeyer.
You can see how those front legs are set forward a bit.
See those bumps on this horse's forehead? Those are the horns.
Having horses with horns, and the anti-Mormon sentiment of the time led to rumors about the horses and their connection to members of the Mormon Church. Cristine wrote about that when we first began discussing having a Moyles horse resin made for us.
August 7, 2001
Oh, Lynn, I am *so* enjoying Christmas in August! The articles you mention
sound fascinating! You know, I actually worked with a sweet Christian woman
at a local university in the music department. I wasn't LDS yet, but I was
investigating the church. She told me in all seriousness that Mormons had
horns. She said you could feel them if you ran your fingers through their
hair and to beware of the men who were wearing hats to cover up the bumps
if they had thin or no hair. I thought then that it was a little strange
and dismissed the notion immediately. But now I look back and wonder that
anyone could truly believe such nonsense .... which this dear lady did!
Cristine ........... =D
Now, Cristine's experience was over 100 years after the Brigham Young/Porter Rockwell era, yet the rumors persist that we, and our equines, have horns to this day.
(Er, in case you are wondering, it's not true. I have no horns that I am hiding under my hair. Abby is hornless, too. Haha!)
And that's how Rockwell, Kathleen Moody's sculpture and Mormon Model Collectors' own "special run" came to be. Quite a ride, and very, very special to me to have been a small part in Rockwell's history.

