When Ernie Hartnagle came home from World War II in 1946, having served two-and-a-half years in the Seventh Pacific Fleet and participated in the liberation of the Philippines, there was no time to relax or recuperate or bask in the plaudits of his nation. Though just 20 years old, he was, like many other young veterans, seasoned by his experiences. And that was a good thing, because his father died while Ernie was away in the Navy, and being the oldest child, it fell upon him to assume the mantle of the Hartnagle family upon his return.

That responsibility included running the family’s 99-acre ranch in Boulder—purchased by Ernie’s parents in 1929, the year of the stock market crash, and held on to with hard work and gritted teeth through some lean and difficult times—and providing for his mother, two brothers, and a sister. He quickly found that the ranch’s yield alone wasn’t enough and began to travel each spring to his Uncle Frank’s Bar-K Ranch in the Gore Range, on land that is today Vail Ski Resort.

There, he and Frank would fatten the herd of cattle by driving them from one mountain meadow to another, chasing the lush, seasonal grasses of the Rocky Mountains. Once summer began to set in, the herd would be based in the high country, at 11,500 feet, but for a period in early May, some of the best grass was found in the pastures in the valley at 8,100 feet. So every morning before dawn, Frank and Ernie would round up the cattle with the help of their stock dogs and drive them 3,400 vertical feet down the hill for a few hours of grazing.

But temperatures rise quickly at that time of year, and if the men and dogs couldn’t get the cows moving back up the steep slopes, which are now blue and black diamond ski runs, to the cooler fields atop the mountains, the cows would grow obstinate and ultimately so troublesome that even the dogs would wither. All of the dogs, that is, except for one.

A couple of Uncle Frank’s dogs were border collies imported from Nottingham, England. The border collie is the world’s unrivaled champion of sheep herding, a breed honed for this specific purpose over hundreds, and perhaps thousands, of years. But border collies were then newer to working with cattle and were certainly not accustomed to covering thousands of feet of elevation gain, at high altitudes and in wildly divergent temperatures, over the course of a single work day.

When the day grew too hot, and the climbs too taxing, (1) these collies, famous for their drive and endurance, would fade and quit just like the cows, while a single black, bobtailed dog named Rover seemed inexhaustible. No matter the temperature, or the elevation, Rover would race uphill and downhill, nipping and barking at the cows until they resumed their march. The only way to get him to stop working was to force him to do so, and Ernie believed that, if not for human intervention, Rover might work himself to death.

Rover was the finest dog Ernie Hartnagle had ever seen, and he resolved to get himself a bobtail or two for his own ranch, once he had the money and could locate the source. At the time, he had no idea where to get one, (2) or how far this special kind of dog, which he’d gotten to know on the slopes of the high Rockies, would take him.

At least in the national consciousness, Colorado is a state with two reputations. There is its historic, pioneering side, which conjures visions of wide-open space and libertarian freedoms and cowboys on horseback ranching sheep and cattle. And there is its modern-day connotation, of ski slopes and national parks and progressive idealism, where healthy, attractive men and women in microfiber garments jog and bike trails and appreciate the state’s natural beauty in more recreational fashion. And there, connecting these two worlds, is the Australian shepherd.

The Aussie, America’s 26th most popular breed, isn’t Colorado’s official state dog, but it really should be. (3) Considered a midsize dog of prodigious energy and high intelligence, its general appearance, according to the official American Kennel Club (AKC) breed standard, “is well-balanced, slightly longer than tall, of medium size and bone, with coloring that offers variety and individuality.” Unlike the standards for many of the fussier breeds, which focus largely on physical characteristics, the Aussie’s official definition is as much about its personality and agility: “He is attentive and animated, lithe and agile, solid and muscular without cloddiness.”

“The Aussie was selected specifically as a generalist,” (4) says Carol Ann Hartnagle, Ernie’s youngest daughter, and she would know. No family has held more sway over this breed than the Hartnagles of Colorado. The primary reason the Australian shepherd has become both the world’s best herding and adventure dog—as well as an excellent companion and a capable guardian—is that the Hartnagle family, and the handful of others who helped shape the breed over the past 75 or so years, embraced its intelligence, drive, and adaptability to create a dog that can and will do just about anything. “The Australian shepherd’s hallmark is its versatility,” Carol Ann, who’s 48, explains. “These dogs just have a high desire to please.”

It’s hard to imagine now, but for nearly 70 years the Hartnagles owned and grazed flocks of sheep inside Boulder’s current city limits. A blue heron rookery was just east of the ranch, and both Boulder and Dry creeks passed through the property. It was in large part on this land, which was also home to a 53-acre reservoir (known today as Hartnagle Lake), that the little blue bobtailed sheepdogs of the American West—defined, in look and character, by Rover, and others like him—became the breed we now know as the Australian shepherd.

There were dogs that looked and acted very much like today’s Aussies a long time before Rover, and certainly before the dogs bred by the Hartnagles. But you won’t find much unanimity in the Aussie community over the breed’s precise origins before the 1940s, at least in the distant sense. Everyone agrees that the dogs are not actually, despite their name, a product of Australia, but beyond that there’s little agreement. What is likely is that the breed as we know it arose semi-organically on sheep ranches in the middle and far West of the United States over a period of many years starting in the mid-1800s.

The best guess of what happened with the Aussie is that a variety of shepherd dogs were working in the western United States—Colorado, Wyoming, Idaho, and California in particular—interbreeding with whatever other herding dogs happened to be working nearby. The gene pool further diversified when dogs from Europe began to arrive in the late-19th century, along with reinforcement flocks meant to replace sheep that had originally arrived with the Spanish conquistadors, but which became lunch during the California gold rush and Civil War. These dogs accompanied sheep that may have been imported from Australia—which is one good guess as to how the name arose. Other shepherd dogs that existed in the West originated specifically in Spain—these were larger dogs—and so the argument can be made that Australian shepherds are largely Spanish, and specifically Basque. (5)

The reality is that it’s impossible to reconstruct an exact history of the Aussie. It’s not uncommon for dog breeds to lack a succinct, annotated history. Although many were very specifically engineered from a traceable set of forebears, (6) others—like the Aussie—just sort of happened by circumstance. The Australian shepherd isn’t Australian, or English, or Spanish. It’s all of the above. Though the best answer of all is that it’s American, with the West, and Colorado in particular, at its core.

By the mid-20th century, around the time Ernie was first smitten by Rover, it had finally occurred to people to start writing things down, and the story of the Australian shepherd began to crystallize. Before that, dogs that appeared to be Aussies were doing their jobs all over the West, but no one seemed interested in documenting their provenance. It didn’t matter to most owners where a particular dog came from, or who its sire was; it only mattered that the dog was good at its job. Very often you will find these dogs referred to in old texts as “little blue dogs” or “little blue bobtails” or, especially among natives in Colorado, “ghost-eye dogs,” and it’s pretty clear that the three common physical characteristics of the Australian shepherd, as it developed organically, were a blue coat, a bobbed tail, and a high occurrence of blue eyes.

The characteristic that led to these dogs becoming a formal breed, however, was the thing that struck Ernie: their ability to “work” livestock—at first sheep, but also horses, cows, ducks, geese, or any other animal a farmer might need to tend to. (7) And because of their remarkable abilities, bobtails began to show up in and around Colorado.

Rover was the dog that first caught Ernie Hartnagle’s eye, but it was a pair of dogs he encountered at a local stock show in 1952 that forever changed the course of his family’s history. There, Ernie met Jay Sisler, a rodeo star whose act starred Stub and Shorty, a pair of blue bobtails who performed dozens of remarkable tricks and became so beloved and famous while part of a touring show that they went on to star alongside Slim Pickens in a 1956 Disney television show titled Cow Dog.

Ernie couldn’t believe what he’d just witnessed at the show—dogs walking for minutes on end on hind legs, or doing handstands atop broomsticks, and any number of other impressive, intricate tricks on command—and after the performance he sought out Sisler, who told him that these off-the-chart smart dogs, which looked and acted like Rover and the other bobtails he’d seen working sheep, were known as Australian shepherds. “We’d never heard that name before,” Ernie recalls, “but we decided then we’d get some of those dogs.”

One year later, in 1953, Ernie met and fell in love with an A&W Root Beer stand carhop named Elaine Gibson, who just happened to have grown up amongst these dogs herself. Elaine knew them as “bobtailed shepherds,” and the Gibsons of Wyoming had owned them as far back as the 1920s, when her grandfather had one he called Bob (for its tail) that he used to bring his colts in from the range to prevent them from being attacked by mountain lions. It’s a funny coincidence, Carol Ann says, “that both of my parents have a very unique history in parallel with these dogs.”

The Hartnagles acquired their first bobtail together the same year they met, a female named Snipper, and very quickly sought to add a second dog like her to the family. In 1955, when Ernie spotted an ad in the Denver Post for “blue Australian shepherds” at an address outside Littleton, he drove down and met Juanita Ely, a “salty ranch woman from Idaho,” as Ernie describes her. Ely got her blue dogs from Basque shepherds, and the animals looked a lot like Rover and Snipper. Ernie and Elaine were thrilled; they’d found their source.

The Hartnagles took home their second Aussie, Badger, and were so taken with his herding ability and courageousness that they went back to Ely again for Goodie, Badger’s half-sister. Those two dogs became the foundation of the breeding program for all the family dogs that would follow.

It was Ely, Ernie says, who is probably most responsible for the Aussie getting its start. Though Ely’s goal was never to open the pipeline, by breeding high-quality blue, bobtailed sheepdogs of Basque origin, Ernie says, “She was the fountainhead.”

Back home in Boulder, Ernie and Elaine began to mate one good bobtail to another with the sole criterion in selection being the dog’s aptitude to work, and the Australian shepherd as we know it today began to take shape. The idea, at the time, wasn’t to build a kennel. “We just liked the dogs. And we liked what we had,” Ernie says. “But I got to thinking, ‘Boy, everybody with livestock should have one of these dogs.’ ”

The Hartnagles started by breeding dogs for themselves in 1955, but word of the Hartnagles’ dogs soon spread across Colorado, and then across the entire western United States: If you needed a good cow or sheep dog, you went to Boulder to see the Hartnagles. Las Rocosa (8) Kennel was christened in 1970, and by then the Hartnagles were averaging about eight litters a year. Today there are four recognized colors for purebred Aussies: the blue merle, the red merle, the red tri, and the black tri, and among the landmark accomplishments to originate at Las Rocosa was the introduction of the red-colored Aussie (in 1970) and the recognition that black dogs, in addition to reds, were just as capable as the legendary blues. “We lifted the black dog out of the cheap seats,” Ernie says. “We said we believed that color doesn’t make any difference. You may like one better, but the black dogs are just as good as the blue dogs.”

To make that statement as clearly as possible, the Hartnagles set a single price for their puppies, regardless of color. This wasn’t just unprecedented; it was revolutionary. Years ago, before the Hartnagles vouched for the quality of red and black Aussies, ranchers often killed the puppies to save themselves from having to raise a dog that couldn’t work. As Ernie explains it now: “People did not understand breeding these dogs.”

Very quickly, red came into vogue, and the Hartnagles figured out that, because the color was a recessive trait, the only way to produce red out of non-red dogs was if both parents had the gene in their backgrounds. Today, breeders can learn the genetic makeup of their dogs through simple DNA tests, but back then, Ernie says, “It was just a step-by-step process. The only way you learned something is you made a mistake.” And when you did, “you made a rule so you wouldn’t make that mistake again.”

The Hartnagles weren’t alone. Colorado became the hub of Aussie activity, mostly because it was a center for American livestock. (The National Western Stock Show was an unofficial gathering for Aussie breeders and enthusiasts.) Las Rocosa—which, in 1991, would become the first kennel awarded Hall of Fame status by the Australian Shepherd Club of America and later became the first to be given Hall of Fame Excellence status—provided many of the foundation dogs you’ll find in the Aussies of today. (9)

The Hartnagles weren’t the only ones pursuing the perfect Aussie. Ernie says that pretty much every Aussie in America has its origins in five basic foundation lines, and all but one of those lines comes from a Colorado breeder. First and foremost, obviously, is Las Rocosa, with the other key players being Juanita Ely, Fletcher Wood, and Dr. Weldon Heard. Whereas Ernie Hartnagle was in pursuit of the ideal herding dog, Heard, through his Flintridge kennel, was chasing a different sort of perfection and was focused more on structure and appearance, which translated well into the conformation ring. (10) Specifically, Heard studied and followed the strategy of old German Weimaraner breeders, who would allow only the top two puppies from each litter to reproduce.

Heard’s impact on aesthetics was especially huge. “Of all the foundation bloodlines,” the Hartnagles write in The Total Australian Shepherd, “the Flintridge line exhibited the greatest influence on the modern show Australian shepherd.” Heard died in 2008, and by that time had stopped breeding dogs. Likewise, the lines of Juanita Ely, Fletcher Wood, and Jay Sisler have also long since ceased. Of the five foundation lines of the Australian shepherd, only Las Rocosa is still active, through the work of Ernie’s two Colorado-based children, Carol Ann and Jimmy.

By the 1990s, the city of Boulder had grown so rapidly that it basically encircled the Hartnagle family ranch. In 1997, Ernie and his family sold it to the city, and it became “open space.” Now, pretty much every day of the year Boulder residents jog and hike on this land, often with Australian shepherds at their sides. Bisected by Boulder Creek, and with sweeping views of the Flatirons, it is some of the most pristine land remaining in the city.

Ernie and Elaine relocated to a smaller, 78-acre ranch near the town of Kiowa, about an hour southeast of Denver, where, in addition to a couple of horses and a donkey named Lila Jane, the couple keeps a pair of Aussies that assist Ernie in his daily chores. Among their jobs: fending off coyotes, rounding up Ernie’s flock of purebred Dorset sheep, (11) and separating specific animals when it comes time for vaccinations. Ernie—tall, broad, and ruggedly handsome even in the second half of his 80s—still shears the wool and on occasion ventures out to judge some of the Australian shepherd herding competitions.

Carol Ann (and her husband, Kenneth Madsen) and Jimmy (and his wife, Lisa) are now the primary torchbearers for the Las Rocosa brand. Carol Ann and Kenneth own nine Australian shepherds ranging in age from three to 15, and the couple still breeds, but no more than one litter a year from their small Adams County farm. She says she can’t remember any part of her life that didn’t prominently feature Aussies. The dogs worked with her siblings in the pastures, and the family traveled to herding competitions (12) on weekends. “I’ve known nothing else than having these dogs as part of our lives as companions and guardians and partners on the ranch,” she told me.

By the time Carol Ann was born, in 1963, Las Rocosa was so abuzz with Aussies that “the dogs almost raised me,” she says, and she’s only exaggerating slightly. One of her earliest memories on the farm, she recalls, is of a dog named Daisy who was entrusted with the very important task of keeping the toddlers away from the long driveway that led to the busy road out front. Daisy was taught to give the kids a certain amount of leeway, but if they reached a certain point, “she would interrupt us and dissuade our path,” Carol Ann says. “She would gently take our hands in her mouth. Her task was to keep us safe. It was amazing.”

Carol Ann says one of the things she’s most proud of is that—despite the fact that official AKC recognition in 1983 caused a spike in popularity that continues to this day, and the fact that the dogs have found a second niche as the go-to breed for the hiking/biking/skiing adventurer—the Australian shepherd is still primarily doing what it was bred for. “A significant number are still raised for real-world conditions,” she says, meaning for working on ranches, with sheep and cows. “Not too many breeds in America that can claim that.” (13)

Though she has a busy career as an executive for a professional records management company, Carol Ann, like her sister Jeanne Joy who lives in Nashville, Tennessee, still travels widely—even sometimes overseas—to judge Australian shepherd conformation and stock trials. One reason she breeds so few litters is that she insists on being present for the births and for the early weeks when the dogs’ personalities begin to develop.

The last time we spoke, in early December, she had a litter of puppies that was just 14 days old. It was a breeding she’d been planning for four years, and when the pups arrived, it was a profound occasion. Both the sire and the dam have lineages that go back to the very first dogs that Ernie and Elaine used to start the Las Rocosa line. These puppies, Carol Ann said, “are the 16th generation of our family program.”

Ernie might no longer have much of a hand in the operation, but Las Rocosa’s impact lives on. “I would say definitely that the breed is synonymous with our family,” Carol Ann says. “Anybody who has knowledge of the breed would understand that, and conversely no one can know anyone in our family without knowing the synergistic connection to Australian shepherds. They’re one and the same.”

Josh Dean is the author of Show Dog: The Charmed Life and Trying Times of a Near-Perfect Purebred, which will be published by HarperCollins this month. His writing has appeared in GQ, Outside, Men’s Journal, and the New York Times. Email him at letters@5280.com.


1. In places, the terrain was so steep that the men had to dismount their horses.

2. The idea that a dog would have a specific, traceable, documented lineage was an utterly foreign idea to Ernie, and probably most people, at the time.

3. There are currently just 11 U.S. states with an official state dog. The honor, believe it or not, requires an act of the state Legislature.

4. This stands in stark contrast to the majority of dog breeds, which were bred with very specific purposes in mind. The dachshund was bred, for instance, to crawl into holes and ferret out varmints, which is why it’s so feisty and prone to tearing small objects to shreds. Another popular ranch dog, the border collie, was refined by the English and Scottish for hundreds of years to work with sheep. It’s a champion of sheep herding, but it doesn’t want to do much else. If you buy a border collie and ask it to be your house pet, prepare for shredded carpets and herded children. That’s because, explains Carol Ann, “a border collie’s desire to please a handler is not greater than their desire to pursue their own instinct.”

5. In the years after World War II, a federal government program, in conjunction with the Western Range Association, granted three-year visas to foreign shepherds who could help fill in for the lack of able-bodied males in the United States. Many were Basque.

6. For instance, the bullmastiff was created by English game wardens to ward off poachers by mixing tenacious bulldogs with hulking mastiffs.

7. Including children. Aussies are famous among farmers for their ability to pitch in with babysitting.

8. Spanish for “the Rockies.”

9. “Foundation dogs” is breeder jargon for the most prominent specific animals in a pedigree. If you trace a modern Aussie’s family tree back far enough, there’s a very good chance you’ll find some Hartnagle dogs in there.

10. That’s a fancy word for dog shows of the kind you see at Westminster in New York City.

11. Numbering 38, Ernie’s flock is one of the largest in the region for this rare breed.

12. These events started, in large part, due to the efforts of Ernie and Elaine to increase interest in the breed.

13. When was the last time someone you knew bought a terrier, for instance, for the primary purpose of killing rats?