We fell in love with grullos several years ago when we were lucky enough to purchase a mare named Ash. She was so striking and unusual and she has been a consistent producer for us. Proven time and time again as not only a docile and well mannered mare, Ash and her offspring have been exceedingly hardy and stoic creatures. We LOVE Grullos and have been fortunate enough to be able to raise and collect a few.

Grullos are a key part of our breeding program and with our solid foundation of proven horses like Holy Smoke, combined with the exceptional Rocky lines of horses like Spanish Lights and Steely Dan, we hope to bring forth an exceptional herd of dun and grullo mountain horses.

Being rare makes them special and in demand, yet it isn't our goal to meet customer demands. Our goal is to produce the best examples of both color and type. Quantity isn't important....quality is. With that in mind, we look forward to looking out into a field of "stripey" horses that are not just consistent in color but in type as well.

Sweetwater's Delightful and Bonsai Wild produced this beauty of a grullo for Elaine in MN. We are envious to be sure! Notice the cross at her withers, the dorsal stripe and the barring right behind her knee, and her black tipped ears. Separately, these markings may or may not indicate dun....but combined they are a sure sign!

While not scientifically proven, we do believe that grullo and dun colored horses are naturally hardy creatures. Of all the horses we have, the grullos always seem to be the easiest keepers, least prone to illness, and very stoic in their behavior. Whether or not any experts will back us up in our theory....we do know from experience that grullos are very tough and hardy horses. 

What is a Grullo?

A grullo (pronounced "grew-yo") is a black horse with a dun gene. Very rare in the mountain horse breeds, duns and grullos have become prized and sought after in recent years.

The dun gene is a dominant gene that dilutes the body color of a horse but not the primitive markings, points, or mane and tail. Dun horses have often been mistaken as buckskins but carry different genetic make-up. What makes the dun gene so special is that it is completely dominant. It affects all base coat colors-- unlike the single creme gene which does not dilute black and the silver dapple gene which does not dilute red. A dun gene will not hide itself. In order to produce a grullo, at least one parent must be a dun colored horse.

Grullos and duns can have various distinct or subtle primitive markings. Most obvious and most necessary is always the dorsal stripe, followed by leg barring, counter shading on the neck which often looks like a cross over the withers, tipped ears, and dark shading on the face. Sometimes there is even "cobwebbing" on the forehead, and frosted guard hairs at the base of the tail and throughout the mane. 

How does one breed for a grullo? The most obvious answer is to breed grullo x grullo. The next best option is to breed grullo x black or any sort of dun x black. Two non dun horses will never produce a dun. There are false duns out there that can quickly be identified as false by checking their parentage for color.

The dun gene combined with another dilution gene, like the silver dapple gene, makes for interesting color. So, what makes the above horse a silver dapple grullo? You have to know the nature of both genes. A silver dapple is a black horse diluted by the silver gene.....a grullo is a black horse diluted by the dun gene. So, we know that the above horse is truly classified as "grullo" and not just dun, because his original base coat is black and been modified by two dilution genes.