BIXBY, Okla. (AP) - A sign on the gate of Ted Allen's ranch in Bixby reads, "There's nothing here worth dying for."

But according to Allen, the not-so-subtle warning did little to save the dozen or more cattle that disappeared from the 480-acre spread in May.

"I was watching a cow every day to see if she had a calf, and I came back one morning and she's gone," Allen said. "Then I realized that we had three or four more missing, and we ended up with at least 12 gone."

Allen, 79, who has been raising cattle on the ranch since he was 16, is convinced it was an old-fashioned case of cattle rustling.

"I didn't think that happened anymore," he said. "I've only seen it on TV and in the movies."

The story has been the same in recent months for dozens of ranchers across the state who awaken to find their cattle missing, sometimes with a cut lock on the gate or tire tracks left by trucks and trailers.

The rate of cattle theft has more than doubled in the past year to about 45 head a month, according to officials at the Oklahoma Department of Agriculture.

Many blame the weak economy.

"We talk about the tough economic times and you talk about the factories closing in the city, but you forget about the rural communities. They're hurting, too," said Tom Troxel, an agriculture professor at the University of Arkansas. "Cattle rustling always seems to go up when the economy goes down."

States such as Texas, Missouri and Montana also report steep increases in cattle rustling, Troxel said.

Cattle rustling might seem like a crime straight out of the Wild West, but modern livestock thieves prey on ranchers by using trucks, trailers, ATVs and a network of nearly 100 stockyards and cattle auctions across Oklahoma, said Col. Mike Grimes, director of investigative services for state Agriculture Department.

Recent beef prices put a cow's value somewhere near $1,000. The price can be even higher for specialty breeds. And unlike stealing a car or tractor, most cattle can be sold for 100 percent of market value.

Earlier this month officials in Choctaw County charged four people with stealing 50 calves from a ranch. They allegedly used a livestock trailer and ATVs to round up the calves before driving them more than 200 miles north to a stockyard near Tahlequah.

All 50 head were stolen in one night, and the owner called law enforcement early the next morning. State investigators were able to track down the suspicious sale within hours.

Each of the four - two men and two women - faces charges of conspiracy to commit a crime and larceny of a domestic animal, the latter of which carries a sentence of three to 10 years in prison, Grimes said.

All four defendants had experience handling cattle.

"We were fortunate to get them because the rancher called us early, and there are only so many stockyards open on a Saturday," Grimes said.

Even though cattle rustlers face steep sentences, Oklahoma's lax animal identification laws, massive beef industry and proximity to major agriculture markets make it difficult for investigators to track down thieves.

The state is the second-largest cattle producer in the country, with an industry valued at nearly $2 billion. But it has no laws requiring ranchers to brand or tag animals, although agriculture officials strongly encourage beef producers to brand.

Most of Oklahoma is also just a few hours from dozens of major stockyards in the Dallas, Kansas City and St. Louis areas, not to mention smaller outfits across the border in Arkansas and Kansas.

"Once they go across the border, we have ways to track them down, but it gets much harder," Grimes said.

Apart from the inconvenience, cattle rustling can be a major economic hit to farmers.

Allen, who raises a specialty breed of Piedmontese cattle known for lean, tender beef, is out at least $12,000 and will likely be missing a whole year's worth of young cattle.

Just down the road from Allen's ranch, Jeff Emerson discovered at least 15 head of his cattle missing July 6.

"There could be more missing because this is calving season," said Emerson, who lives in Owasso and doesn't visit the Bixby ranch every day. "They could have been doing it once a week for the last five weeks."

Emerson thinks he's out about $3,000 for each cow because he raises "natural" beef and sells them at two stores he owns in Tulsa.

"It's already bad just because of the economy," he said. "With this, I feel like I'm running a nonprofit."

By KYLE ARNOLD Tulsa World

Copyright 2009 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.