By 1935, sheep raised in the United States were numbered at 51.8 million with 60 percent being raised in the western states. David Cook, who was the foreman for the Warren Livestock Company in Wyoming from 1920 to 1961, wrote, “From the time sheep were introduced into Wyoming, the dog has played an important role in the sheep industry. If not for the assistance of these faithful animals, herding large numbers of sheep would have been impossible. Many times the dog saved the lives of sheep and herders, especially in storms. When a storm suddenly appeared, the herder could not have gathered the herd and brought them to shelter had it not been for the dogs.”
Raising good sheep dogs was a necessary part of any large sheep operation. The shepherds needed dogs that were fearless and could stand up to an obstinate ram. It was customary to give each herder a pair of working dogs and a pup. That way, if anything happened to one of the dogs, he would have another to fall back on. After many years of working almost all breeds of sheep dogs including the old fashioned farm collies, Cook, said, “For our purpose, the small blue and white Australian, often with a so-called “glass eye”, became the most satisfactory dog we used.” The ranch acquired their first pair, named Maggie and Jiggs. “These dogs turned out to be the breeding stock which was used to produce our future generations of sheep dogs.”
According to Cook, one of the main reasons Australian Shepherds were preferred over the old fashioned farm collie was due to their stamina and power to move large numbers of sheep in the harsh western conditions of the open range. In discussing the old-fashioned collie, sometimes referred to as Old Shep, Cook described them as good winter dogs. “It could stand the cold weather, but became sluggish in hot weather. However it was a good all around dog with the ability to work with changing herders. Pups learned fast, but due to big feet and heavy weight, were very susceptible to sore feet and required a lot of food.” Old Shep was reliable, but lacked staying power for wide-spread sheep ranching.