Guapo's freedom ended one chilly morning on the grounds of a prison yard surrounded by snow-capped mountains and shrubby plateaus.

The shaggy, sleepy-eyed mustang was loping freely through the mountains of southern Nevada only a few months ago. But he was caught during a federal roundup, tamed by a prison inmate at the Northern Nevada Correctional Facility and put up for adoption on Feb. 13 - one of about 9,000 wild horses that will be captured by the federal government this year.

The saga of America's wild horses is as mythic and divisive as the West itself. It's a story replete with outlaws, brawls over land, disputes over who the West really belongs to and what freedom actually means.

Critics say the government, in trying to control what it says is an overpopulation of mustangs, is systematically wiping out the species. Federal officials say they're protecting horses like Guapo from starvation and disease and saving the rest of the West from habitat loss.

"This is a highly emotional, very challenging issue with a lot of ethical implications," said Barry Perryman, associate professor of rangeland ecology at the University of Nevada-Reno. "If we do nothing, within a generation we'll have a million horses on the range, at the expense of everything else, from kangaroo rats to antelope."

Horse advocates say the horses should be left alone. If they are overpopulating, nature should be allowed to take its course. Banning the hunting of mountain lions, the horses' primary predator, is a good place to start, they said.

"The government is managing horses to extinction," said Ginger Kathrens, an Emmy-winning Colorado filmmaker who heads a nonprofit devoted to the plight of mustangs. "If some of them starve, well, so do elk and deer. Just let them be."

36,000 wild horses

An estimated 36,000 wild horses roam through 10 western states, including California. Some are descendants of the horses that arrived with the Spanish 500 years ago.

Their population sprang from horses that had escaped or had been abandoned and adjusted to life in the craggy mountains and shady gullies of the West. By 1900 more than 2 million mustangs wandered the western landscape, according to the American Wild Horse Preservation Campaign.

But as the West became less and less wild, the horses' freedom was reined in. Much of the West's great open expanses are now controlled by the Bureau of Land Management, a federal agency charged with protecting 256 million acres of open space.

Among other things, the bureau issues permits for livestock grazing on more than half its holdings, so the horses must share food, water and space with cattle and sheep.

Grazing permits are a money-maker for the government, earning about $17 million in 2008.

Competing with livestock

This is where the horses run into trouble. According to the bureau, the horses are overgrazing land meant to be shared with livestock, and overgrazing in general leads to erosion, reduced water quality and an increase in invasive species. And without sufficient food and water, the horses are likely to starve or suffer serious health consequences.

So in the 1970s, after Congress passed the Wild Free-Roaming Horses and Burros Act, the government started rounding up wild horses and relocating them. Crews use helicopters to scare a herd of horses into running anywhere from 3 to 10 miles into a portable corral, where they're checked by veterinarians, sorted by sex and age, and the males are castrated. About 9,000 horses a year are captured by the government. In some cases, herds are thinned by 80 percent.

"We try to do this as safely and humanely as possible," said Alan Shepherd, who oversees the bureau horse program in Nevada. "It's not a perfect system, but overall we're doing pretty well, I think."

At a recent roundup in Nevada's Calico mountains, 39 of the 1,922 horses removed from the range died. Most of the deaths were due to "extremely poor body condition" because of the lack of food, according to the bureau.

The roundups have enraged animal rights activists, some of whom have staged elaborate rallies and demanded congressional inquiries, saying the practice is barbaric, costly and pointless.

After the roundups

Most of the mustangs captured by the federal government are sent to one of dozens of pastures in the Midwest or large corrals scattered throughout the West, where they join about 32,000 other captive mustangs and spend the remaining 20 or 30 years of their lives. About a third of the captured mustangs are offered for adoption to the public.

As any equestrian will attest, keeping horses is not cheap. In 2008 the government paid $27 million to feed, shelter and provide veterinary services for its captive mustangs.

The Obama administration is looking at alternative ways to control the herds, which officials say are growing by 20 percent a year due to lack of predators. Obama has proposed nearly doubling funding to pay for birth control and to create wild horse preserves where the public can view these elusive beasts.

In addition, with wild horse adoptions down 60 percent from a decade ago, mirroring the horse market generally, the government wants to offer takers $1,500 incentives.

"Adopting a horse is a very rewarding experience that we very much want to promote," said bureau spokesman Doran Sanchez. "It's not just good for the horses, it's an amazing bond that develops between the adopter and the horse. These horses are extraordinarily intelligent and truly unique."

Critics say the government should shrink the program, not expand it.

"If there's no market, there's no market. The (bureau) should not be rounding up more horses than can be adopted," said Virginie Parant, director of the American Wild Horse Preservation Campaign. "They just end up stockpiling more horses."

The horses deemed adoptable - those that are younger, healthier and more docile - are trucked to facilities across the country where they're either trained, in most cases by inmates, or sold as-is.

The government sponsors about 50 horse sales a year, with prices ranging from $125 for untamed mustangs to more than $4,000 for horses that have undergone three or four months of intensive training at prisons.

Not just anyone can adopt a mustang. The government requires potential owners to have equestrian experience, access to land and a corral, financial resources and time for training. The bureau keeps the deed to the horse for a year and periodically checks on the horse's welfare before turning over the ownership papers, said bureau spokesman Sanchez.

Unfortunately, it's not easy to find a home for a horse that has a strong aversion to humans, especially in the current economy. Feeding, caring for and keeping a horse in a barn in Contra Costa County, for example, could cost $8,000 a year, an expense few are willing to assume as jobs continue to evaporate.

About 150 people showed up for the horse auction at the prison yard of the Northern Nevada Correctional Facility to bid on 18 horses that had undergone four months of training by inmates. The bidders stroked the horses' muzzles and chatted with the inmates about the individual horses' quirks and dispositions.

Partial to mustangs

Want-ads may be full of horses for sale, but it's hard to top a mustang, bidders said. Wild horses tend to be stockier, more muscular and resilient.

"I love these horses because they're like the American people - strong, true, honest, a hodge-podge of everything," said Anni Herborn, who fell in love with Guapo the moment she saw him on a bureau Web site.

"Watching that horse, I know it's worth it," said Herborn, a PG&E electrician who paid $1,200 for Guapo at the Feb. 13 auction. "He's an angel. I am absolutely thrilled."

Herborn, who has a ranch outside Oroville, adopted another wild horse at a bureau auction last year, and said she couldn't be happier with the shaggy, stocky additions to her barnyard.

"They're smart. They're wise," she said. "They're survivors."