Utah members of the Animal Liberation Front claimed responsibility for the Sept. 21 raid and another on Aug. 19 in South Jordan in which breeding records were destroyed and 800 pens opened.

The attacks are a blow to a big industry in Utah. The state ranks second only to Wisconsin in mink production, producing 1.5 million pelts annually. Sixty-six farms in Utah raise more than 620,000 minks annually and the pelts are valued at almost $41 million, according to Fur Commission USA.

"Nobody is putting anyone out of the mink business," said Ryan Holt, who spent last Sunday helping to round up minks freed from the Kaysville farm. "If anything, it's turning people against the animal rights movement."

Holt's own Salt Lake County mink farm was targeted in 1996 when vandals jumped a fence, spray painted "blood money" on buildings and broke into cages, freeing 3,000 minks.

Federal agents say the Animal Liberation Front is organized around small, separate cells akin to organizations such as the Irish Republican Army, making investigation difficult. The group believes that "non-human animals deserve to live according to their own natures, free form harm, abuse and exploitation," according to the group's Web site.

Operation Bite Back: Investigators became aware the ALF was targeting universities and private businesses associated with the fur industry in 1991. The first victim was Oregon State University in Corvallis, when the university's experimental mink farm was set on fire with a timed incendiary device.

In the ALF's so-called Operation Bite Back, attacks in 1991 also were launched against a Washington mink food plant, a fur animal research facility at Washington State University and an Oregon mink ranch that was burned to the ground.

That same year, attackers also singled out the Fur Breeders Agriculture Coop in Sandy. The Utah mink food plant sustained damage and graffiti left there was consistent with an ALF raid, investigators said. The coop was the target of several other attacks, culminating in a 1997 explosion and fire that caused nearly $1 million in damage.

In 1992, an arson fire at a Michigan State University research lab was linked to a bombing that same year in the coyote research center at Utah State University in Logan.

The ALF also was blamed for a 1996 raid on a Coalville mink farm. The attackers destroyed breeding records and released 670 minks and foxes from pens. Two other farms in Salt Lake County were raided that same year.

Breeders began patrolling their farms at night, installing electronic sensors on barns and fences and getting unlisted telephone numbers.

Raiders return: Raids against fur farms seemed to subside after the 1990s, perhaps because several members of the group were arrested and imprisoned in Utah and other states. This month, an ALF statement acknowledged the lull in raids, saying, "Good news, haven't seen this done in a while so it had to be done."

Five days after the South Jordan raid in August, about 6,000 minks were released from a British Columbia farm (the operation was first attacked in 1995) and on Sept. 4, hundreds of mink were released on a fur farm in Scio, Ore.

"It seems we may have an eco-terrorism road trip in progress, attacking farmers in two countries," said Teresa Platt, director of Fur Commission USA, a trade group representing about 300 mink farms in 24 states. "Our experience has been it's a handful of people in a car moving across state lines. When the cops take out two or three people, the attacks die out."

Damage also comes from the loss of breeding information.

Each mink's cage has a card with that animal's pedigree and life history. The animals themselves are not tagged. Since there is no way to match recaptured animals with their cages, years of selective breeding information is lost.

Minks are bred for size, fur quality and variety of pelt colors, many of them rare or unknown in nature, according to Fur Commission USA. This includes white, plus a host of shades of black, brown and gray, sometimes with tinges of blue or pink.

Utah fur farms do well because of the state's cold winters, which strengthen pelts, said Larry Lewis, spokesman for the Utah Department of Agriculture and Food. In addition, many of the growers are third-generation farmers who also benefit from the Sandy cooperative their grandfathers had formed.