A rare black mule deer that wandered around the redrock of Moab — and who residents there lovingly nicknamed “Coal” because of his uncommonly dark fur — died last month from chronic wasting disease, officials confirmed Monday.

The presence of the neurological disease, revealed in a necropsy, have prompted some concern among wildlife experts that it is spreading among the other deer and elk in the area. So far, it’s the sixth deer in the La Sal Mountains and the 16th in the state to test positive since July 2019.

Roughly 60 other sample results from animals across the state are still pending.

The infection, which is often compared to mad cow disease, causes lesions to form in an animal’s brain. It is not transmittable to humans, but in deer, elk and moose, it’s fatal — and can easily transmit among them. Chronic wasting disease, or CWD, first showed up in Utah in 2002 when a buck mule deer killed during the rifle hunt near Vernal tested positive. Since then, tens of animals in the state have contracted it. Most are in the eastern and central parts of Utah.

“The Division of Wildlife Resources takes CWD very seriously and conducts extensive monitoring each year to stay on top of the disease and its prevalence in the state,” according to a news release the organization sent out Monday.

What’s more unusual in this case is the deer that died from it.

“Coal” was a 3-year-old buck mule with black hair, a condition caused by an overproduction of melanin. It’s estimated that condition appears in only 1 in several million deer. That makes it even less common than an albino (all white hair) or piebald mule deer (white spotted hair), according to the Utah Division of Wildlife Resources.

“This unique deer touched a lot of people’s lives in this area,” DWR conservation officer Adam Wallerstein said. “Coal is responsible for putting smiles on a lot of faces during his life. The community will feel his absence.”

The deer was beloved in Moab, where many saw him and a few lucky residents were able to snap a picture of him. Coal was found dead in a resident’s yard on Dec. 17, and the community has rallied to have him preserved through taxidermy and memorialized. He would likely be displayed in a public building in Moab.