SNOWFLAKE, Ariz. (AP) Kent Knudson had been fed up with cows wandering onto his property for years. So when he came home one afternoon and found a herd in his back yard, he promptly got his .22-caliber rifle and fired.

A red-and-white pregnant cow fell to the ground kicking, and died by Knudson's shed.

Problem was, Knudson violated open-range law, a remnant of the Old West. And he learned the hard way that cows still rule the range: He was handcuffed and jailed, charged with a felony.

Since that day in January, Knudson has gained supporters and lost friends, nasty letters have been written to local newspapers and the shooting has opened up a new debate about whether open-range laws are too outdated for the new, more urban West.

``You're really dealing with the Old West crashing into the New West,'' said Courtney White, executive director of the Quivira Coalition, a Santa Fe, N.M.-based group that helps ranchers and environmentalists work together.

``The old days, the cows just wandered around. One-hundred years ago that was fine. Today it's a problem.''

The way Knudson tells it, he didn't really mean to kill the cow. But he does admit aiming at the herd on Jan. 15 after the animals trampled his septic line and ate his plants and trees. He said he was just protecting himself and his 77-year-old mother, who suffers from Alzheimer's disease.

Knudson, a freelance photographer, has a fence to keep cattle out, but had forgotten to close his gate when he rushed his mother to the hospital three days before because she had a mild stroke.

Under open-range law, cattle can roam and graze at will. It is up to the property owner to fence out cattle if that is his wish; the owner of the cattle has no obligation to restrain his cows.

Thirteen Western states have some form of open-range law, most similar to Arizona's. California has the most limited, with open range only in six counties.

East of Colorado, the rest of the country long ago did away with giving cows free roam, but open range has remained prominent in the West as a relic of the past, when cattle easily outnumbered people and it made sense to let them wander. Parts of the West do have so-called ``no-fence districts,'' where landowners petition local governments to require ranchers to fence in their cattle in certain areas.

Across the West, yellow signs warn of open-range territory along roads and highways, and mean the driver, not the rancher, is liable for hitting a cow with a vehicle. Near Yellowstone National Park, Wyoming adds a definition for tourists, warning that they should expect cows wandering on the highway.

``Some of these laws are so backward,'' said Greg Schneider, a member of RangeNet, a group trying to change cattle grazing laws.

``People didn't care about it in the past because it wasn't impacting them,'' he said. ``But that's changing, because of the population changing, people becoming more mobile and living farther out....''

Home on the range has gotten a lot more crowded as the West undergoes a huge population boom. From 1990 to 2000, the region had the largest growth in the country 19.7 percent, to 63.2 million people. As the population increases and new residents move into rural areas, open-range laws have gotten more attention and more controversy.

Ranchers, fiercely protective of their cowboy way of life, resist any suggestion that they should cave in to the changing of the times.

``If it ain't broke, don't fix it,'' said Steve Pilcher, executive vice president for the Montana Stockgrower's Association. ``It ain't broke.''

In Montana, where cattle still outnumber people, a case involving a woman injured when her car struck a cow prompted the state Supreme Court to rule in December 2000 that ranchers were not exempt from liability if their livestock roamed onto roads.

Ranchers cringed, fearing their beloved open-range was changing. But within a few months the Legislature passed a new law declaring that a livestock owner is not responsible for damages in such cases, barring gross negligence.

``Open-range has been that concept, whether you agree with it or not, that has been the code of the West for 50, 75 years. It's always been accepted,'' Pilcher said.

He and other ranchers argue that changing the laws to require ranchers to fence in their property would cost too much and likely put them out of business.

A few miles outside Snowflake, a small Mormon community in northeastern Arizona, Knudson, 53, steps off his back porch in rural Navajo County and leads the way to the scene of the crime. He gestures to the patches of dirt and trees, where he said he found about 30 cows that January afternoon, then points toward his shed.

``The cow died right there, right in front,'' he said.

Knudson doesn't understand why he shouldn't be allowed to protect his property, his mother and himself. Despite living here off and on since grade school, he said he didn't know he would get in trouble for shooting cows on his property.

``I can't have cattle running around in here,'' he said. ``I tried to get them out, tried to shoo them out and it wasn't working. I had to get the cattle out.''

Hence his decision to use a rifle. He said he called the cows' owner, rancher Dee Johnson, before he fired shots, but Johnson wasn't home at the time and he left a message with Johnson's wife. The next morning, Johnson, 64, called Knudson and was told one of his cows was dead.

``I said, it's dead from what? He said it either broke his neck or I shot it,'' Johnson said. ``I said if you shot it, we're on opposite sides of the issue.''

After a sheriff's deputy investigated, Knudson was handcuffed and hauled off to jail, charged with unlawful killing of another's livestock. He has pleaded innocent, and the case is scheduled to go to trial in November. If convicted, he faces up to two years in prison.

Knudson started firing off e-mails and letters, insisting he was wronged and that the laws must be changed.

He ended up losing a few close friends who thought he shouldn't be so vocal, but did gain sympathetic supporters who were just as frustrated.

``We don't want open grazing anymore,'' said Penny Leslie, 61, who lives on 500 acres of land outside nearby Show Low and said cattle have trampled her fence. ``Do away with it.''

After Leslie heard about Knudson's case, she started going door-to-door, getting phone numbers and opinions on the open-range law. She made a list of neighbors who have had run-ins with cattle farm equipment destroyed, cattle running down fences, dogs killed by ranchers and hopes it will help change Arizona's law.

But ranchers say Knudson and his group just don't understand the ways of the West.

Johnson said it doesn't make sense to modify open-range laws, mainly because the West has so much open space even with a growing population.

``It isn't practical and it wouldn't work,'' he said.

That's mostly because of the makeup of the West. It has far more state and federal land than the rest of the country and it takes more land to run cattle because of the dry climate.

``We think all people should respect the fence laws that are in place,'' said Jeff Eisenberg, director of public lands council for the National Cattlemen's Beef Association. ``Whether or not they need to be updated, there's nothing about this story that suggests why they would have to be.''

``Mostly everybody I know, they're sick of hearing about it,'' said Carroll Cox, editor of the Snowflake-Taylor Pioneer newspaper, Knudson's hometown newspaper.

The newspaper as well as the White Mountain Independent in Show Low have published testy letters on both sides of the issue.

``Why don't you take your medicine like a man?'' a reader wrote in the Snowflake paper in reference to Knudson. ``Why don't you just stop all this nonsense?'' another wrote to the White Mountain Independent.

``It's obviously stirred up a group to continue writing,'' said publisher Greg Tock. ``It's kept the letters to the editor coming in.''

Knudson isn't stopping at letters to the editor. He plans to lobby the Arizona Legislature and Congress, and says he will not accept a plea bargain in the case against him. He vows an appeal if convicted.

``I guess the question for the 21st century is, should a black cow at midnight have more right to a highway than a person?'' asked Andy Kerr, director of the National Public Lands Grazing Campaign, which is trying to get Congress to pay ranchers to give up federal grazing permits.

``These laws have been on the books since before Henry Ford invented the automobile. How fast could you go in a horse and buggy? The law hasn't kept up with reality. Open-range laws may have made sense in the 1800s, but they don't make a lot of sense today,'' Kerr said.

But updating a remnant of the Old West will likely take more than Knudson's grassroots effort. After all, ranching and the cowboy lifestyle are part of the West's heritage.

``All of the things that people think about in the West, what's the first thing people think about? Ranches and cowboys,'' said Doc Lane, director of natural resources for the Arizona Cattlemen's Association.

``It happens to provide one heck of a lot of money for this nation. The public ought to think about that. All we want is the opportunity to make a profit. We're not going anywhere.''

Terence J. Centner, a professor of agricultural and applied economics at the University of Georgia, has written several articles about open-range laws and the need for reform, but doubts serious change will come anytime soon.

``People don't like change, and they don't like to change laws,'' he said. ``It would be very difficult to change these laws. That's what they've grown up with.''

For now, Knudson continues to write his letters and e-mails, always ending them with his motto: ``Cage cattle, not people.''

He knows now what can happen on the open range in the West. And he hasn't closed his gate since.