The three-day roundup of wild horses in the isolated Disappointment Valley north of Dolores in September was an unqualified success in the opinion of the wild horse specialist for the Bureau of Land Management in Colorado.
“This was the first time there – and I think in the state – that we’ve been able to adopt 100 percent of the mustangs,” Fran Ackley said. “We did really well, much better than in 2007.”
Spring Creek Basin in the Disappointment Valley is one of four locations in Colorado where the BLM manages wild horse herds. There, mustangs roam just less than 22,000 acres of rolling hills and stark uplands.
During the Sept. 16-18 roundup, called a gather, about 50 horses of the 80-plus Spring Creek Basin mustangs were separated from the herd into corrals by a helicopter pilot. One horse was euthanized after it broke its neck from running into a corral wall, and another was removed from the herd because it carried a ranch brand.
Twelve mustangs were released, among them five mares that received a primer injection of an anti-fertility vaccine called PZP, the first step toward sustainable herd management.
“This could be the turning point in herd management,” said Pati Temple, a board member with the Colorado chapter of the National Mustang Association.
Twenty-five horses were selected for later adoption in Cortez, and a dozen considered less adoptable were sent to the BLM short-term holding facility in Cañon City.
As it turned out, all the horses – including the mustangs sent to the holding facility and four that weren’t snapped up at the Cortez adoption – have been adopted or spoken for, Ackley said.
“The Disappointment Wild Bunch Partners (a local mustang advocacy coalition) deserves credit for the success of the adoption,” Ackley said. “They got out a huge crowd at Cortez for the day-before preview and the adoption on Sept. 24.”
The mustang – the name derives from mesteño, Spanish for a stray animal – has a mixed origin. The ancestors of some arrived with the waves of Spanish adventurers while others descended from horses lost, stolen or turned loose as the population pushed westward. During the Great Depression, many horses were released when owners couldn’t maintain them.
The presence of wild horses in the Disappointment Valley appears to date to the late 1800s when rustlers arrived with horses stolen in Montana to sell to the Army for cavalry mounts. In the 1940s, area ranchers removed many horses but left a few.
Gus Cothran at the Department of Veterinary Integrative Biosciences at Texas A&M University in College Station, Texas, traces mustang ancestry through DNA for the BLM.
Cothran, who has a doctorate in genetics from the University of Oklahoma, said during a telephone interview that he prefers hair samples rather than blood to study DNA because hair is easier and less expensive to obtain.
The Spring Creek Basin herd has very limited Iberian ancestry, he said. They have more Morgan and Thoroughbred in them, said Cothran, who has collected genetic information on 179 BLM herds.
Cothran said the genetic variability of the Spring Creek Basin herd is low. He said the recent roundup could heighten the possibility of undesirable inbreeding unless young mares are introduced.
Nine mustangs have been introduced to the herd in the last two decades – three stallions from Wyoming in the 1990s, three mares in 2001 and three mares in 2008. The stallions came from Wyoming, and the mares came from Sand Wash Basin Herd Management Area in northwestern Colorado.
Apparently all of the horses gathered this year from Spring Creek Basin will spend their days in Southwest Colorado – Cortez, Mancos, Telluride and Ridgway.
Among the adopters was Tif Rodriguez of Mancos, who ended up with two horses.
Rodriguez, a self-employed legal transcriptionist, had her eye on a 2½-year-old stud colt, a grandson of Traveler, a stallion identifiable by a spectacular grey coat and admired for his patriarchal grandeur. She also adopted a foal born in early September.
Dana Ivers, an outfitter and guide from Telluride, adopted a 2-year-old colt, a yearling colt, a 2-year-old filly and a weanling filly.
“I took them to save them from prison,” Ivers said, a reference to the Cañon City holding facility. “We’re going slowly, but we already have them bridle trained.”
The females are more approachable because they lived in a family environment while the stallions roamed in a band of bachelors, Ivers said.
“The stallions are wary and fearful of predators,” Ivers said. “They are still in their safety bubble, so you have to approach them carefully.”
Ivers said she might one day make the mustangs part of her outfitter’s herd.
“But I can’t see a hunting dude on one of them,” she said.
Temple has four mustangs on her Trail Canyon Ranch near Cortez, including an 18-month-old gelding, a son of Traveler, that she adopted Sept. 24. Offspring of Traveler’s are favorites because they tend to be tractable, she said.
Temple will accustom the colt to ranch life but won’t ride him until he’s 4 years old.
Horses are among the 14 large-mammal species that are able to be tamed, Temple said. The same as people, they need to be part of a social unit, she said.
“They live to 25, so there’s no reason to hurry,” Temple said. “By 4 years old, they’re more mature in the brain, so it’s safer for the rider.”
The BLM has about 3,000 mustangs at its holding facility in Cañon City. Inmates at the nearby state prison care for the equines and are saddle training 50 at any given time, Ackley said.
The U.S. Border Patrol adopts most of the saddle-trained mustangs, he said.
The Wild Free-Roaming Horses and Burros Act approved by Congress in 1971 ordered protection of wild horses and burros as symbols of Western heritage. Under the legislation, the BLM is to maintain herd levels in accordance with the ability of the range to sustain them.
Kiley Whited, a rangeland management specialist at BLM’s Tres Rios Field Office in Dolores, said the appropriate management level of Spring Creek Basin is 35 to 65 mustangs. Forty-two horses live on the range now.
The inoculation of mares with the anti-fertility vaccine would help control herd growth, he said.
Inoculating mares from a distance with a loaded dart was started in the Little Book Cliffs herd area near Grand Junction as a research project in 2002 and has continued as a management strategy after the research ended in 2007.
The number of foals there has declined from 30 to 40 annually to 11 in 2010, making a roundup unnecessary this year and maybe next year.
Debate continues about whether mustangs are wild or simply feral because of their earlier domestication and whether the Przewalski’s horse of Mongolia is the only true wild horse because it has never been tamed.
The wild-versus-feral debate is applicable to the Spring Creek Basin herd, where movement is limited by fences and natural barriers, where horses share the range in winter with cattle and some of their water sources are man-made.
The BLM adheres to definitions in the 1971 legislation. Among them: “Wild and free-roaming horses and burros means all unbranded and unclaimed horses and burros on public lands in the United States.”