The buck was found and tested after being hit and killed by a car in Grand Teton National Park.
Wildlife officials say that though they are concerned, it is not surprising.
Cases of the disease have been seen in other parts of the state in recent years.
Game and Fish researchers have been testing game in Northwest Wyoming, and so far, no elk have tested positive but officials say it is likely that will change.
Though the disease has not been shown to be transmissible to humans, the CDC says we should not consume any meat that we think might be infected.