Authorities are continuing to investigate the death and mutilation of five bulls on a remote Eastern Oregon ranch.

The bulls, worth about $7,000 each, were found dead and mutilated — with genitals and tongues cut out — on Silvies Valley Ranch in Harney County, Ore.

Two carcasses were discovered July 30. On July 31, three more carcasses were found.

The cause of death is unknown, but investigators suspect one or more people are responsible.

Harney County Sheriff’s Office Deputy Dan Jenkins is the primary investigator. The Oregon State Police and the Malheur National Forest Emigrant Creek Ranger District are also on the case.

As of Aug. 7, according to Joshua Giles, a forest ranger with the district, the investigation continues with no clear leads.

As an isolated incident, the case might appear a strange fluke. But according to the FBI, thousands of killings and mutilations of cows have happened since the 1970s. The animals typically die in the same way with the same body parts removed.

Jenkins said it’s hard to tell how these five bulls died. There are no entry wounds. A metal detector scan revealed no bullets.

According to National Weather Service data, the past month has had no major lightning storms in the area that could have killed cattle.

Based on the lunar calendar from the 2019 Farmer’s Almanac, the deaths could not have happened during a full moon.

Colby Marshall, vice president of Silvies Valley Ranch, said there were no outward signs of a struggle — no rope burns on trees, no scattered hoof prints, no strangulation marks, no blood. The bulls, he said, look like they simply fell over and died.

“Maybe they were poisoned,” said Jenkins. But if they were, it could not have happened by natural causes. Jenkins said Ty Campbell, the property owner’s son, along with Clint Weaver, the cow boss, scoured the property looking for poisonous plants but found none.

Jenkins said a necropsy to determine the cause of death was not possible because when the bulls were found, they were already past the 24-hour window when a veterinary inspection would have been effective.

Marshall, the ranch’s vice president, said the bulls had probably been dead for two to three days when they were found.

The 4- and 5-year-old registered Hereford bulls were on the 140,000-acre ranch and resort in Seneca, south of John Day. Dr. Scott Campbell, a veterinarian, owns the ranch.

The average value of a Hereford bull, said Shane Bedwell, chief operating officer at the American Hereford Association, is $5,000. However, because of their genetic line, Marshall estimated the bulls at Silvies Valley Ranch were worth about $7,000 each.

Marshall said that even though livestock workers are on the property with the cattle every day, it’s a rough, forested terrain so it’s understandable that the bulls weren’t found for a few days.

“People always seem surprised that a cattle rancher wouldn’t notice some of his animals are dead right away,” said Jerome Rosa, executive director of the Oregon Cattlemen’s Association. “What they don’t realize is the enormity of these properties. Unless you’re in a plane or helicopter, you can’t see everything that’s happening.”

Even stranger than the deaths, said Jenkins, are the mutilations. Only a few parts of the carcass were removed on each animal — the anus, scrotum, testicles and tongues. One bull was also missing its penis and the tip of one ear.

According to Rosa of the OCA, it’s not unusual to find small body parts missing in natural predatory cases. When coyotes and wolves find a carcass, Rosa said, they often go for the easy pickings first, chewing off parts like testicles and tongues.

What’s strange about this case is that the areas with missing parts don’t appear to have been chewed. Jenkins, the deputy, said the wounds, when examined, appeared clean-cut.

“The parts were definitely cut out with a sharp blade,” he said. “There weren’t any signs of predatory eating or chewing. They were cut out by at least one person.”

The Oregon Cattlemen’s Association has offered a reward of up to $1,000 to anyone who can provide information leading to the arrest and conviction of whoever is responsible. A separate $25,000 reward is also being offered by an interested party.

“Whenever there’s a case like this, all the conspiracy theorists come out,” said Jenkins. “Some say it was done by aliens. Others say it’s a cult doing a satanic practice. Some even think it’s the government. It’s a little ridiculous. I’m confident some person or group did this, and we’re trying to get to the bottom of it.”

Those with information about the case, said Jenkins, should call the Harney County Dispatch Center at 541-573-6156.

Marshall, of Silvies Valley Ranch, advises ranchers and other people to be careful.

“This is a very dangerous situation,” said Marshall. “I want people to be extra careful to protect themselves and their livestock. It makes me sick that our gentle bulls were killed and mutilated in this way.”

Marshall said that since the case opened last week, other farmers across the West have contacted him to share their similar stories of livestock mutilation.

“People are looking for answers,” he said. “But right now, we don’t have any.”