Mustangs occupy a unique position in the nation's history and culture, evoking visions of untamed, open space and sturdy steeds that helped settle the West.

But their reality has long been compromised by human interests — their tale one of changing priorities, political pressures and shifting policy.

Though now wild, these majestic herds trace their roots to domesticated horses first brought to America by Spanish settlers in the 1500s. For centuries, their descendents roamed across the valleys and hills that would one day make up the Great Plains and the western United States.

"I think that these animals have a rightful place in the wild, on the range," said Sonoma Valley wine producer Ellie Phipps-Price, who has joined a campaign to stop the federal government from rounding up wild horses.

But despite 1971 legislation calling for their protection, some 301,000 horses and burros have been removed from public lands over the past four decades. Today, about 31,500 horses — 37,300 if one includes burros — still run wild, living across 10 western states, though more than half are in Nevada.

But federal regulators say the area cannot support even that many. The Bureau of Land Management, which is tasked with managing the long-term health and productivity of the land, believes the range can only support about 26,500.

One of the agency's mandates is to maintain limits on mustang populations by removing "excess" animals from public lands, using helicopters to drive them into temporary corrals. Most are transferred to long-term holding pastures, primarily in Kansas and Oklahoma, where they will live until they die.

But the government is running out of space to store the animals.

The BLM currently has 50,000 mustangs in holding areas, at a cost of $43 million to American taxpayers last year. It managed to place more than 2,500 horses and burros through its adoption program, but there just isn't enough demand to keep pace with those taken from the land.

"We're in a bind," BLM spokesman Tom Gorey said. "We don't have a quick fix to our holding situation. We are reaching capacity. We're approaching maxing out."

Advocates for the horses say the problem arises from abandoning the 1971 congressional act that prohibits the killing of mustangs and wild burros after decades in which their populations were nearly decimated. The Wild Free-Roaming Horses and Burros Act declared these creatures the "living symbols of the historic and pioneer spirit of the West" and prohibited their "capture, branding, harassment, or death."

But the bill was amended in a few short years as the mustang population rebounded, reaching an estimated 60,000 by 1976. The U.S. Secretary of the Interior was soon authorized to establish maximum herd sizes and cull horses deemed "excess." The round-ups, which typically involve helicopters used to drive the horses from their grazing lands into fenced areas are sometimes grisly affairs, with horses thrashing violently to break free, resulting in injury and, occasionally, death.

A last-minute, 2004 legislative rider slapped onto an appropriations bill further undermined the '71 act, stripping the protective status from mustangs older than 10 or unclaimed after three passes at adoption. The measure permitted their sale to the highest bidder, even if it meant their commercial slaughter.

The BLM has never implemented that provision. However, it is likely that at least 1,777 sold to a Colorado man for $10 a head ended up as meat, in violation of the sales contract, according to an investigation last year by ProPublica, the nonprofit public interest news group.

Gorey said the BLM has an advocacy role for the mustang but is managing the 245 million acres in its jurisdiction for "multiple uses," including the nearly 27 million acres of wild horse range. It must balance the needs of livestock grazing, wildlife habitat and human recreational use, while defending against erosion and destruction of watersheds.

The mustang, Gorey said "is the most emotional issue of all the issues that come under our bailiwick, and that's why it makes news so much."

The fate of the mustang is in part due to its own success in reproduction in the near-absence of natural predators. The population grows about 20 percent a year without intervention, Gorey said.

Cattle and sheep ranchers say the wild horses compete for forage with their herds and damage public rangeland.

Critics, however, argue that the cattle still outnumber the mustangs by a vast margin — far more than the 20-to-1 ratio the BLM says are on the range at a given time.

Mustang advocates contend the horses are being sacrificed to preserve low-cost forage for cattle. The beneficiaries, they say, are a small number of ranchers who pay $1.35 per animal for each month of grazing access on BLM lands, enjoying a federal subsidy equivalent to $58.3 million, according to a 2005 study by the U.S. Government Accountability Office.

"The horses get thrown under the bus every time," Phipps-Price said.

(You can reach Staff Writer Mary Callahan at 521-5249 or mary.callahan@pressdemocrat.com.)