The existence of the Spanish Mustang today is largely due to the actions of a very few people working together to set up a Spanish Mustang Registry as well as the Southwest Spanish Mustang Association. The Spanish Mustang Registry was first established in 1957 by a man named Robert E. Brislawn of Wyoming. Mr. Brislawn lived the life of the cowboy, working on various ranches and eventually owning his own. He very much valued the hardy, strong and courageous horses that he noted were decreasing in numbers every year. In 1925 Mr. Brislawn traveled through the western United States, looking for the ideal Spanish Mustangs to start a breeding herd to preserve the lineage. Originally started with two stallions, one which reverted back to its wild state, Brislawn and his brother began breeding Spanish Mustang mares and stallions, allowing them to live on the huge pasture land and grazing reserves in Wyoming. Several of the horses bred out of the original two stallions are still considered some of the highest quality Spanish Mustangs today with championships in endurance and trail riding all along the bloodline. The emphasis in breeding was constantly on keeping the physical appearance, endurance and stamina that the wild Spanish Mustangs had to have to stay alive on the open prairies and plains.
As word spread around the county of the Brislawn Spanish Mustang preservation efforts other Spanish Mustang breeders and lovers came forward to join the registry. In 1957 there were just 20 Spanish Mustangs registered, but at the last count there are over 3000 Spanish Mustangs, all bearing the conformation and type of the true Spanish Mustang on the registry. Other registries now exist so the exact number of Spanish Mustang horses is not known, but they are not considered a rare or endangered breed thanks to the dedication of the first individuals that recognized the value of the breed and made great efforts to preserve and protect the Spanish Mustang.
The Southwest Spanish Mustang Association was also started by a man that truly loved and enjoyed working with this breed of horses and had also been part of the development of the Spanish Mustang Registry with Robert Brislawn. Gilbert Jones started the Southwest Spanish Mustang Association in 1977 and served in the association until 1998. This association keeps a list of registered breeders of Spanish Mustangs as well as works to promote the heritage and character of the Spanish Mustang and to preserve the breed as a true heritage horse. This association is based out of Oklahoma where there are still almost pure strains of Spanish Mustangs that have been kept by various Native Indian tribes and have been relatively isolated from breeding to other types and breeds of horses.
With the many different colors and patterns possible in the Spanish Mustang and the endurance, intelligence and athletic ability of these horses becoming better known, the demand for Spanish Mustangs continues to grow. While most Spanish Mustangs are now bred in captivity, there are still some wild Spanish Mustangs that the various associations work to preserve and protect in their wild state.