LA SAL, San Juan County — There's no real explanation, nothing that would lead biologists to believe deer on the LaSal Mountains are any more likely to contract chronic wasting disease than deer anywhere else in Utah.
But the fact is that of the 13 known cases in Utah, eight deer came from the little cluster of mountains southeast of Moab.
The latest case was a deer shot last month during the muzzleloader hunt and was the one positive result in 100 deer checked.
Still, biologists are puzzled and are concentrating their attention on the LaSals in an attempt to find out why.
The first case in Utah of CWD was found two years ago in the mountains northeast of Vernal. There have been four positive tests in deer from the same area.
"We can explain these cases. It was found in deer just across the border in Colorado and was likely brought into Utah through that herd," reported Leslie McFarlane, wildlife biologist for the Utah Division of Wildlife Resources.
"We're not sure how it got into the LaSals. It didn't come from Colorado. Colorado does extensive testing, and CWD hasn't been found in deer across the border. There are no private elk ranches in the area and no natural migration routes, so we really don't know where it came from."
Starting this winter, the DWR plans to focus its studies on the LaSals. Among other things, it will closely monitor the migration patterns of the deer to see if it could have come from outside the area.
Testing thus far has shown a prevalence rate of around 2 percent, which is much lower than test results from either Colorado or Wyoming. In some units in Colorado, 15 percent of the tested deer had CWD, and in Wyoming the prevalence rate in some units is 23 percent.
"What this tells us," McFarlane said, "is that the disease is new here in Utah. Colorado or Wyoming have probably had the disease for a long time. It is believed, now, that some of the early diagnoses were wrong. So little was known about the disease at the time."
This past weekend, the DWR set up a special check station just outside the town of La Sal to collect tissue samples from deer shot in the area during the state's general deer hunt.
Samples from about 150 deer were taken on the archery and muzzleloader hunts. Bill Bates, wildlife program coordinator in the DWR Southeastern Region, who ran the station, hoped to have another 150 samples before the hunt ended on Wednesday. The hunt in the LaSals in one of the units holding a five-day hunt instead of the statewide nine-day hunt.
By late Monday afternoon, he was about 25 samples shy.
Bates said hunters coming off the LaSals over the weekend were not overly concerned with the presence of CWD.
"Everyone seemed to be aware of the disease, but most said they'd hunted the area for years and were not worried," he said.
None of the hunters contacted on Monday by the Deseret Morning News was overly concerned.
Earl Koskie of Pleasant Grove, who tagged one of the largest bucks checked by the crew, a 7 1/2, 4-by-4, said he isn't worried.
"My family has been coming here for six years and pulled, maybe, 20 to 25 bucks off this mountain, and we've never had a problem," he said as he watched Bates take tissue samples.
"I'll take the deer home and start making jerky."
Jimmie Lee Torres of Magna, who along with two other women took two deer off the mountain, said she is not worried, but would wait for the test results before eating any of the meat.
Garry Hicks of Reno also said he is not bothered by the CWD reports but also would wait for test reports before cooking up any of the steaks.
Chronic wasting disease infects only deer and elk. It is in the same family of diseases as mad-cow disease, which has been transmitted to humans. It is also in the same group as Creutzfeld-Jakob disease, which is fatal to humans. And it is similar to scrapie, which has been around for more than 300 years and infects sheep but not humans. There is no evidence that CWD can be passed to humans.
The disease, found three decades ago along the Wyoming-Colorado border near Cheyenne, has begun to spread to other parts of the country the past couple of years. In most cases the cause has been traced to private elk ranches.
Biologists are still trying to determine how the disease is spread from one deer or elk to another.
"The one thing we do know, now, is it's spread laterally, from an infected deer to another deer. It can also be transmitted in the environment, when a live animal comes in contact with a dead animal that was infected," she added.
"It has to be direct contact, however, through the saliva or feces."
It is also believed it can be spread during mating rituals followed by bucks during the rut.
The 13th case of CWD was found last year in a deer that was acting strangely in a pasture near Fountain Green, Sanpete County. It, too, is a mystery.
Again, there is no logical explanation for how that deer became infected. There are no natural migration routes from either of the areas where the disease has been found and no private elk ranches in the area.
"What we did here," McFarlane said, "was what we call 'hot-spot culling.' We removed 100 animals from the same area and none tested positive. Again, we have no explanation for this case."
Plans are to test 3,200 deer this year. Last year the DWR tested 3,167 deer.