Biologists are focusing on LaSals' diseased deer

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.