The Sulphur herd management area horses are generally Spanish in type, and should be managed to enhance this characteristic. Other populations of feral horses that are Spanish in origin are very rare (Pryor Mountain MT, Marble Canyon AZ, and Kiger OR, although these last are varying from Spanish phenotype more than the others). Since the Spanish feral horses are the only feral horses of truly unique and irreplaceable genotypes, they should be manager as a genetic resource in addition to other BLM requirements.

In the case of the Sulphur herd I recommend that target population levels be set that are consistent with this population being able to sustain itself without needing introductions of outside, non-Sulphur, horses. This maintenance would assure its continuation as an unique herd of Spanish horses. I also recommend that for the next several years the removal/adoption process concentrate on removal of the least typically Spanish and retention of the most typically Spanish horses. This process may be difficult for a few years, with removal of some older animals. It must be stressed that the broad front is not typically Spanish, while the deep body with narrow chest is.

Following the first few years the removals should only have to involve younger animals that are of less Spanish appearance. The long term management should quickly develop into the removal of younger animals that are surplus to the population, but these should all be of Spanish type as the population becomes more uniform for this type. Given the remarkable uniformity of the population already, this process should not take very long.

The Sulphur herd is minimally variable for color, and this variation should be maintained. I only saw bay, black, chestnut and the line-backed modifications of these (zebra dun, grullo, and red dun). I suspect that on some portions of the range other colors persist since they are mentioned in the herd management plan. It is important to not cull these. The preference for the line-backed colors is based on myth, and these colors do not imply that the horses are more Spanish than those lacking these colors. The same is true of the white marks: they are perfectly allowable. While the appeal of the line-backed colors is undeniable, the other colors should be maintained at levels that prevent their extinction.

The Sulphur Herd Management Area brochure is good and informative, but I would recommend a few changes.

First, late additions to the herd are only speculative, and since the herd is so consistently Spanish in type I would concentrate on that. Also, I would point out that various colors (not just the line- backed ones) are consistent with a Spanish origin. I like the stripes, but they can be overemphasized to the point that people equate them with Spanishness, which is inaccurate. Another technicality is that there really is no such thing as a "Spanish Barb".

The Spanish Colonial type horse is the foundation of these mustangs. The Barb is a North African horse, descended originally from Iberian horses. Finally, some conformational details on the drawing could be more Spanish (narrower front, finer face/muzzle, sloping croup). These points are picky, but the brochures do a great job of educating, and accurate details will help in the education process even more.

List of Sulphur Management horses inspected, August, 1993 by Sponenberg and Roubidoux. Excellent = top third, Good = middle third. Horses listed in the order in which they were seen, check with Ron for names of owners.

first stop
dun filly good
grulla filly somewhat coarse, bottom third.
chestnut filly good, but has big chestnuts.
black foal good, difficult to be certain due to age.
Trujillo stallion - bottom third. Roached back, head somewhat coarse. bay gelding - not typical. grulla gelding
good, well conformed and Spanish in appearance. grulla mare and foal - good, typical red dun Jones mare
excellent in type. grulla Torres filly - excellent, finely made, Front is good. grulla foal - good to excellent,
depending on how facial width develops. chestnut mare - very wild, appears to be in bottom third. Large chestnuts. Jensen dun stallion - good, head lacks definition (as I remember) one stop, I forget the guy's name black colt - bottom third, largely due to broad face.
sorrel filly - somewhat better than colt, but still bottom third.
bay stallion - excellent. The best roman profile, and a very assured,
classy animal. He is one of the best overall animals.
Grant grullo stallion - Common head, bottom third. Lack of stallion attitude.

Duce animals:
dun stallion - bottom third, wide front.
grullo stallion - good, but head could be more typical. dun filly - excellent, very typical. black filly - good

Steve Hart animals:
red dun gelding - bottom third. High croup.
black colt - excellent, very typical
grullo colt. Excellent. very typical

bay female, bottom third (wide front, the most common fault)
red dun female - bottom third
red dun stallion - too wild to evaluate

dun stallion - stocky, but excellent
grulla mare - excellent
grulla filly - excellent
grulla foal (.filly) excellent
bay mare - poor. large, wide, and wide faced.
dun older filly - bottom third or lower, from bay dam
dun younger filly, better, but still bottom third.

Overall: These horses cluster very nicely as a Spanish type population. They are generally soundly conformed, in addition to the Spanish type. The most common of the deviations from Spanish type are the wide fronts, wide facial areas, long ears, and large chestnuts. These horses that are not typically Spanish are still well conformed on average. This should make them very adoptable and serviceable. Basically, even the nonSpanish horses in the group are good horses, just of the nonSpanish type.

March 1999 by D. Phillip Sponenberg, DVM, PhD

The Spanish Mustang is a direct lineal descendant of the Spanish Colonial Horses that were brought to the New World during the Spanish conquests. These horses persist today in three major ways. One of these is in a relatively few and highly isolated feral herds. A second is in the herds of traditionally minded Native Americans. The third way is through the activities of well organized breeders and ranchers who have used this type of horse.

The organizations that have sprung up from this conservation effort include the Spanish Mustang Registry, the Spanish Barb Breeders Association, the American Indian Horse Registry, the Southwest Spanish Mustang Association, the Kiger Mustang Association, the Pryor Mountain Horse Breeders, and the Florida Cracker Horse Association. These seven organizations have largely relied upon the activities and interests of a variety of interested and motivated individuals. The history of their activities is largely to identify and accept as purely Spanish those horses that meet external, historical, and occasionally blood type evaluation.

It is an opportune time to expand the activities of the existing organizations to include a more active search for and inventory of the remnants of Colonial Spanish horses in the USA. To date this has not happened, but instead the organizations have relied on interested others to bring horses or herds to their attention. The result has been that pure horses outside the organizational structures have not been documented nor recognized, and these are the horses that are in danger of slipping away unnoticed by the organized conservation efforts.

The main places that this search should occur are among the feral BLM herds of horses, and among the horses of the Native Americans. While it is certain that herds of purely Spanish horses of these sources will be rare, it is equally true that even the few that might still exist are of great conservation interest.

Current conservation efforts within the various organizations are functioning well and are focused. They have done a good job in securing most of the Spanish horse genetic resource that is present in the USA. This success means that the major interest in outside horses is mainly in herds of appropriate type and history There is no longer any need to consider the rare individual horse that turns up, unless such an individual is extremely good and very extremely Spanish.

Any other individual horses, especially if they are more average, are simply not important enough in terms of the entire population to warrant much activity. In contrast to these individual horses are entire herds or groups of horses of Spanish type. These larger groups are very significant to the conservation of the Colonial Spanish horse in the USA, especially.

Colonial Spanish Horses are of great historic importance in the New World. They descend from horses introduced from Spain, and possibly North Africa, during the period of the conquest of the New World. In the New World this colonial resource has become differentiated into a number of breeds, and the North American representatives are only one of many such breeds throughout the America. These horses are a direct remnant of the horses of the Golden Age of Spain, which type is now mostly or wholly extinct in Spain. The Colonial Spanish horses are therefore a treasure chest of genetic wealth from a time long gone. In addition, they are capable and durable mounts for a wide variety of equine pursuits, and their abilities have been vastly undervalued for most of the 1900s.


The Colonial Spanish Horse is generally a small horse, although size is increasing with improved nutrition and some selection among breeders. The usual height is around 14 hands (56 inches, 140 cm), and most vary from 13 to 14.2 hands. Some exceptional horses are up to 15 hands high or slightly more. Weight varies with height, but most are around 700 to 800 pounds. Distinctive conformational features include heads which generally have straight to concave (rarely slightly convex) foreheads and a nose which is straight or slightly convex. Some convexity is the classic Spanish type head, in contrast to the straighter nasal profile of most other breed types. The heads vary somewhat between long, finely made heads to shorter, deeper heads. Both are typical of North American Colonial Spanish horses.

From a front view the cranial portions of the head are wide, but the facial portions are narrow and fine. The muzzle is usually very fine, and from the side the upper lip is usually longer than the lower, although the teeth meet evenly. Nostrils are usually small and crescent shaped when the horses are resting and at ease, but do flare with alertness or exertion.

The horses typically have narrow but deep chests, with the front legs leaving the body fairly close together. It is difficult to describe this aspect of conformation without making it sound defective, when in actuality it is a strong, serviceable conformation. When viewed from the front, the front legs join the chest in an "A" shape rather than straight across as in most other modern breeds that have wider chests. The chest is deep from the side view, and usually accounts for about half of the height of the horse from the ground to the withers. The shoulder is long and well angulated. The withers are usually sharp instead of low and meaty. The croup is sloped, and the tail is characteristically set low on the body. The rear quarters vary from fairly massive and heavily muscled to a more slenderly built and less excessively muscled conformation. From the side there is usually a break in the curve of the hind quarter somewhere in the area of the base of the tail, rather than the full even curve of the Quarter Horse from top of croup to gaskin. From the rear they are usually "rafter hipped" meaning that there is no distinct crease at the backbone, but rather the muscling of the hip tapers up so the backbone is the highest point.

The muscling is characteristically long and tapering, even in the heavily muscled individuals, rather than the short and bunchy muscling characteristic of bulldog Quarter Horses and draft breeds. Leg conformation is generally sound, with ample angles in the joints and strong, harmonious relationships between the lengths of the varying parts of the limbs. Hooves are small and upright rather than flat. The chestnuts (especially rear ones) and ergots are small or missing altogether.

These horses usually have a very long stride, and many of them have gaits other than the usual trot of most breeds. These other gaits can include a running walk, single foot, amble, pace, and the Paso gaits of other more southerly Spanish strains (Peruvian Paso and Paso Fin). These gaits refer to the pattern of the footfall, and not to any sideward tendency of the path of the foot. It is important to not confuse the pattern of footfalls with this lateral motion. While both are typical of some of the Paso breeds, only the pattern of footfalls is the actual gait.

It is widely held in some circles that these horses consistently have only five lumbar vertebrae. Work on Barbs, Criollos, Thoroughbreds, and Arabians in Argentina suggests that the Colonial Spanish horses are more likely to have five than are most other breeds, but that a substantial number of pure Colonial Spanish horses also have six lumbar vertebrae. They do usually have short, strong backs regardless of the number of vertebrae.

Colors of the Colonial Spanish Horse vary widely, and it is through the Spanish influence that many other North American horse breeds gain some of their distinctive colors. Colonial Spanish Horses come in a full range of solid colors including black, bay, brown, chestnut, sorrel, grullo, zebra and red dun, buckskin, palomino, and cream. Other solid colors such as the champagne colors, and even silver dapple, occur rarely. In many horses these base colors are combined with white hairs or patches to result in gray, roan, paint (tobiano, overo, and sabino types), pure white, and the leopard complex of blankets, roans, and dark spots usually associated with the Appaloosa breed. The frame overo pattern is especially interesting, since it is almost entirely limited to North American Colonial Spanish horses or their descendants. From that origin the color pattern has spread to other regions and breeds, but all evidence points to its being a Spanish pattern originally. Different breeders select for various of these colors and patterns, but all can be shown to have been present in the Spanish horses at the time of the conquest.


Various registries have had an important role in conserving the Colonial Spanish horses. They have also focused their breeding on a specific type of horses, which is the type described above. This type varies somewhat from the rangier, more lightly built individuals to others that are more compactly and more heavily made, but the range is fairly narrow between these two types. The original Spanish type was probably more variable, including some horses with higher set tails, broader chests, and rounder conformation generally. Conformation details also vary among horse breeds of the Americas that descend from the Colonial Spanish horses.

This variability in the other breeds of Spanish descent calls into question what is truly Spanish type in horses. Certainly there is some wisdom in the registries limiting the range of allowable types in order to produce consistent, predictable horses. It is equally important to recognize that some horses that are considered outside the type desired by the registries are still entirely of pure Spanish breeding. It is worthwhile to recognize that horses of newly found purely bred Spanish Colonial horse herds may be more variable than the present horses in the registries. The registries then usually accept only some and not all of the horses from these herds, although the horses may indeed all be of purely Spanish breeding.

The reasons for the registries not accepting some of what might in act be Spanish types are based in the history of the conservation of Colonial Spanish Horses in North America These horses were originally saved as a small minority of horses in the midst of a large population of horses based on Spanish breeding but then deliberately crossed with draft, Thoroughbred, Morgan, and other types derived from northern European breeding. The range of Spanish types that are likely to be refused registry cannot really be told externally from other types, such as horses with Quarter Horse or Thoroughbred ancestry. Even though some horses with such an appearance may be purely Spanish, they do pose a much greater risk of introducing outside genetic influence than do those horses of the more uniquely Spanish types that cannot be confused with these other breed influences. By concentrating on the most unique of the Spanish types the registries have also assured that this rare genetic resource has been conserved with minimal contamination. The registries are to be commended on their foresight for saving the most unique of the Spanish phenotypes, even if in the process some pure horses were left out.

Colonial Spanish Horses are rarely referred to by this name. The usual term that is used in North America is Spanish Mustang. The term Mustang generally carries with it the connotation of feral horse, and this is somewhat unfortunate since many Colonial Spanish horses have never had a feral background. The important part of the background of these horses is that they are Spanish. These are descendants of the horses that were brought to the New World by the Conquistadors, and include some feral, some rancher, some mission, and some native American strains. Colonial Spanish type is very rare among modern feral mustangs, and the modern Bureau of Land Management mustangs should not be confused with Colonial Spanish horses, as the two are very distinct with only a few exceptions to this rule.

The Spanish Colonial Horse is the remnant of the once vast population of horses in the USA. The ancestors of these horses were brought to the New World by the Spanish Conquistadors and were instrumental in their ability to conquer the native civilizations. The source of the original horses was Spain, and this was at a time when the Spanish horse was being widely used for improvement of horse breeding throughout Europe. The Spanish horse of the time of the conquest had a major impact on most European light horse types (this was before breeds were developed, so type is a more accurate word). Types of horses in Spain at the time of the founding of the American populations did vary in color and type, and included gaited as well as trotting horses. The types, though variable, tended to converge over a relatively narrow range. The origin of these horses is shrouded in myth and speculation. Opinions vary, with one extreme holding that these are an unique subspecies of horse, to the other extreme that they are a more recent amalgamation of Northern European types with oriental horses. Somewhere in between is the view that these are predominantly of North African Barb breeding. Whatever the origin, it is undeniable is that the resulting horse is distinct from most other horse types, which is increasingly important as most other horse breeds become homogenized around a very few types dominated by the Arabian and Thoroughbred.

This historically important Spanish horse has become increasingly rare, and was supplanted as the commonly used improver of indigenous types by the Thoroughbred and Arabian. These three (Spanish, Thoroughbred, and Arabian) are responsible for the general worldwide erosion of genetic variability in horse breeds. The Spanish type subsequently became rare and is now itself in need of conservation. The horse currently in Spain is distinct, through centuries of divergent selection, from the Colonial Spanish Horse. The result is that the New World remnants are very important to overall conservation since the New World varieties are closer in type to the historic horse of the Golden Age of Spain than are the current horses in Iberia.

The original horses brought to America from Spain were relatively unselected. These first came to the Caribbean islands, where populations were increased before export to the mainland. In the case of North America the most common source of horses was Mexico as even the populations in the southeastern USA were imported from Mexico rather than the Caribbean. The North American horses came ultimately from this somewhat nonselective base. South American horses, in contrast, tended to originally derive about half from the Caribbean horses and half from direct imports of highly selected horses from Spain. These later imports changed the average type of the horses in South America. This difference in founder strains is one reason for the current differences in the North American and South American horses today. Other differences were fostered by different selection goals in South America. Both factors resulted in related but different types of horses. At one time (about 1700) the purely Spanish horse occurred in an arc from the Carolinas to Florida, west through Tennessee, and then throughout all of the western mountains and great plains. In the northeast and central east the colonists were from northwest Europe, and horses from those areas were more common than the Colonial Spanish type. Even in these nonSpanish areas the Colonial Spanish Horse was highly valued and did contribute to the overall mix of American horses. Due to their wide geographic distribution as pure populations as well as their contribution to other crossbred types the Colonial Spanish Horses were the most common of all horses throughout North America at that time, and were widely used for riding as well as draft. In addition to being the common mount of the native tribes (some of whom measured wealth by the number of horses owned) and the white colonists, there were also immense herds of feral animals that descended from escaped or strayed animals of the owned herds.

The Colonial Spanish horse became to be generally considered as too small for cavalry use by the whites, and was slowly supplanted by taller and heavier types from the northeast as an integral part of white expansion in North America. In the final stages this process was fairly rapid, and was made even more so by the extermination of the horse herds of the native Americans during the final stages of their subjection in the late 1800's. The close association of the Spanish Horse with both native American and Mexican cultures and peoples also caused the popularity of these horses to diminish in contrast to the more highly favored larger horses of the dominant Anglo derived culture, whose horses tended to have breeding predominantly of Northern European types. The decline of the Colonial Spanish horse resulted in only a handful of animals left of the once vast herds.

The relatively small handful of horses that persisted through the lean years has founded the present breed, and so is the horse of interest when considering the history of the current breed. The foundation that persisted through the period of low numbers will forever stamp the resulting breed in more important ways than will the millions of these horses that once roamed the continent.

Many of the purely Spanish horses in North America remained in isolated feral herds. Such pure horses became rare fairly early in this century due to the practice of shooting the Spanish stallions and replacing them with draft or blooded stallions in an attempt to "improve" or "breed up" the feral herds as sources of draft or remount stock. Bob Brislawn, founder of the Spanish Mustang Registry in 1957, used many feral horses in his herd. Several of his foundation horses were obtained from Monte Holbrook, an Apache living in Utah who was an excellent mustanger (capture of feral horses). In addition to his abilities as a mustanger were those of his wife, Sadie, and their daughter and son. All had reputations and abilities equal to Monte's. Most of the feral component to the Brislawn horses was from Utah, although isolated horses from other herds contributed as well. The Brislawn horses contributed widely to the present breed. Most of the feral herds that served as the original source for the Spanish Mustang Registry were subsequently contaminated with other breeds of horses, and are therefore no longer purely Spanish. The horses within the SMR represent the only contribution that those once pure herds can now make to the breeding of the Colonial Spanish Horse.

A later and major source of feral Spanish Colonial type horses were the herds in the Bookcliffs of Utah. These horses also figure prominently in the Brislawn as well as some other herds. In some herds these are still present as a unique strain, but their main impact has been their use on horses of other strains.

The Sulphur herd management area in Southwest Utah is one area that still has Spanish type horses today. This region is along the Old Spanish Trail trade route, along which many horses traveled during Spanish and later times. Both traders and Ute Indians used routes through the area repeatedly, and the feral horses are thought to have originated from this source. Chief Walkara and others made many horse raids into California, and it is likely that the horses in this region have a California origin, making them distinct from other feral strains. Many of the horses from the northern end of this management area have very Spanish type. The usual colors in these herds are dun, grullo, red dun, bay, black and a few chestnuts. These horses show remarkable adaptation to their harsh environment. These horses are currently attracting attention, as well as dedicated breeders such as Ron Roubidoux. A group of these horses was accepted into the SMR in 1994, and a second group in 1995. The horses remaining in the wild are in a remote area, and these horses are frequently harassed by a variety of people. Hopefully the ones in the feral herds can be managed to complement the very able work being done by Ron and the other breeders. blood typing by Gus Cothran has revealed a very high frequency of Iberian markers in the Sulphur horse.

                                                                                             Credit source D. Phillip Sponenberg, DVM, PhD 

Detailed historical background of the Sulphur herd management area horses is not available. The limited amount of history available points to this population being an old one, with limited or no introduction of outside horses since establishment of the population. The foundation of the herd is logically assumed to be Spanish, since this the only resource available at the time of foundation.

Spanish type includes sloping croup low set tail, deep body, narrow chest, deep Roman nosed head from side view, broad forehead but narrow face and muzzle from front view, eyes place on side of head, small ears with inwardly hooked tips, small or absent rear chestnuts, small front chestnuts, potential of long hairs on stern area and chin. All colors are possible, although a high proportion of black and its derivatives are consistent with a Spanish origin. Line backed duns, roans, buckskin/palomino, sabino and overo paint, and the leopard complex are also usually Spanish in origin, and gray and tobiano can be. It is frequently the mix of colors and their relative frequency in the population that is more important than the presence of absence of any one color.

The horses removed during the last few years from the Sulphur Herd management area are Spanish in type. Thirty four horses were inspected during my visit. Of these 10 were of excellent Spanish type, 10 were of good Spanish type, and 10 were only moderately Spanish in type (although some of these were excellent, if nonSpanish, horses), and four were clearly different from-generally acceptable Spanish type. The fact that the horses were so consistently Spanish type is evidence that these horses have a Spanish origin. Most of the inspected horses fit into the Spanish description. Those that deviated from it tended to have wider fronts than desire and somewhat broader or coarse heads. Roman noses were not prominent, though, and so some of these "atypical" animals still had very acceptable conformation as horses, but lacked the typical Spanish appearance desired. Some ears were long, and some lacked, the inward hooking tips. Chestnuts were usually moderate and not small; some were large. Black and grullo were common, with bay and zebra dun common as well. Chestnut and red dun were also present, but less common. This is consistent with a Spanish origin, although it would be interesting to determine if other colors occur in other parts of the range.

Gus Cothran has blood typed a small number of these horses, and is struck by the frequency of antigens known to be of Spanish origin. While further sampling would be useful, he is confident that this population will ultimately prove to be one of the more consistently Spanish of feral populations so far studied.
Design by "Wiley Coyote Super Genius"
Sulphur Horse History
Sulphur Horse History
D. P. Sponenberg, DVM, PhD, Veterinary College, VPI, Blacksburg, VA 24061 703-231-7666
The Sulphur Herd Management area horses that are present as adopted horses in the Salt Lake City area appear to be of Spanish phenotype. The horses were reasonably uniform in phenotype, and most of the variation encountered could be explained by a Spanish origin of the population. That, coupled with the remoteness of the range and blood typing studies, suggests that these horses are indeed Spanish. As such they are an unique genetic resource, and should be managed to perpetuate this uniqueness. A variety of colors occurs in the herds, which needs to be maintained. Initial culling in favor of Spanish phenotype should be accomplished, and a long term plan for population numbers and culling strategies should be formulated. This is one population that should be kept free of introductions from other herd management areas, as it is Spanish in type and therefore more unique than horses of most other BLM management areas.