THEY don't need unemployment insurance, and they will work weekends without complaint.Herding dogs have had more staying power than the cowboy on the range lands of the Northwest as the livestock industry has looked for ways to cut costs. Hundreds of black and white border collies take to the range every day to help ranch hands herd sheep and cattle. They are at work from the Teton range of southeast Idaho to the flat lands of the Yakima Valley of Washington, and elsewhere. Wool sells for the same price now that it fetched in 1931 and lamb meat fares little better. Faced with those facts, mutton conductors (sheep ranchers) have found the traditional herding dog makes good business sense. The speedy dogs have also found favor on cattle ranches as an inexpensive alternative to extra men on horseback. "Dogs have been in the industry for years and years," says John Dyer, who manages the 4,000-head O X cattle ranch in Hell's Canyon on the Snake River in south central Idaho. He encourages his herding hands to work with dogs because they get more done faster. The rugged hill country where Mr. Dyer ranches is tough on horses and has made him a believer in herd dogs. "If you ever ride in steep country there's just so many places you can't go that a dog can," he says. Highly intelligent, border collies are relatives of herding dogs that have been at work for generations in the highlands of the British Isles. Thousands of miles away from their homeland, they still circle clockwise around a herd of stock at the command: "Come by me.Away to me" sends them counterclockwise. "Steady on" sends them stalking, sometimes crawling, straight at a herd of sheep or cattle, and "That'll do" brings them to their master's side. Even amid Idaho sagebrush, the command to stay put Stand is often pronounced "Stond," the way a Scot or a Brit might say it. But it's more than tradition that keeps the dogs in use. "A stock dog has been a real integral part of the wool grower's operation since day one," says Stanley Boyd, executive director of the Idaho Woolgrower's Association. "Since labor has become more expensive and harder to get, the importance of the dog in the operation has increased." To a sheep rancher, a good border collie is worth three or four men. "Without a pretty good stock dog," Boyd says, "you wouldn't have a range sheep industry." That sentiment's not restricted to the Northwest. Casey Fogt, the publisher of Working Border Collie Magazine, says there is growing interest in the use of border collies on ranches in many parts of the country. For example, she says she recently met a Florida pig farmer who uses border collies to move his boars and sows. "They're everywhere and they're getting to be more popular as people become more aware of their ability to handle livestock," Ms. Fogt says. Exact numbers are hard to come by, but she notes there are 2,000 subscribers to her magazine. In the dog handler's quiet answer to the cowboy's rodeo, herding-dog competitions are growing in popularity along with the use of working dogs. Fogt, who publishes her magazine from Sidney, Ohio, sees or reads of about 200 dog trials a year from the east to the west coast of the United States. Back out on the range, Lori McKinney, a ranch hand at Dyer's O X ranch who also raises and trains border collies, puts the dogs' task in perspective: "The thing about border collies is that's really all they want to do. They aren't working dogs, they're playing dogs. They're doing what they want to do and that's their purpose in life, as far as they're concerned."