How did CWD end up on the west side of the state before being discovered on the Eastern side where it’s bordered with areas that have CWD already?

Good question Kyle and one that doesn’t have a straightforward answer, or any complete answer really. The short answer is we don’t know how CWD got established in Unit 14, but we were as surprised as anyone. We determined CWD was most likely to show up in Idaho where we share a border with Montana or Wyoming, both of which have CWD. It seemed likely that at some point one or more CWD-positive animals could find their way to Idaho. We already know we have mule deer and elk that migrate back and forth between Idaho and those two states.

It’s possible that a CWD-positive animal or animals came into Idaho from Montana, but we don’t have anything to support or refute that. There’s been very little CWD sampling by either Idaho or Montana in much of that Bitterroot country around the border. However, it’s a long ways from Unit 14 to any known CWD-infected herds in Montana. The closest known infections are in white-tailed deer in Montana’s Ruby Range in Unit 332.

It’s also possible that people unknowingly brought CWD into Unit 14 by bringing one or more CWD-positive animals into the unit, either alive or dead. It’s possible that an Idaho resident hunting deer in a CWD-positive state harvested an animal (most likely a deer) that was infected with CWD and unknowingly brought it back to Idaho, processed it and dumped the carcass out in the woods. 

We’ll know a lot more about CWD in Idaho after this hunting season when we will have thousands more samples to help us understand CWD distribution and prevalence, but that may not help us learn anything about how it got into Unit 14 and we may never know unfortunately.