Disease Spreads in Bighorn Sheep in Little Belt Mountains
Last week, Montana Fish, Wildlife and Parks (FWP) reported the deaths of nine bighorn sheep, which had been reintroduced to the Little Belt Mountains southeast of Great Falls. The cause: pneumonia. The disease has apparently spread to other members of the herd.
FWP noted the sheep came from the Missoula River Breaks in 2020 and 2021. The 83 bighorns were released in the eastern Little Belts and all were radio-collared. Because the animals have been tracked with the GPS collars, officials said that, since the reintroduction, they had not come in contact with any domestic sheep, which has often been the cause of pneumonia infections in the past.
However, two bighorn ewes that were transported from the Missouri River to the Little Belts this past winter were found to be carrying the bacteria. Further testing of the Little Belt herd is continuing. Though pneumonia has not been seen in the Missouri Breaks sheep for years, FWP will be monitoring the animals.
Bighorn sheep have been in Montana for hundreds of years. Lewis and Clark saw them as they passed through in the 1800s. In 1916, there were an estimated 1,500 sheep in Glacier National Park. At that time, most of the sheep were in western Montana, with some along the Missouri River in eastern Montana. However, due to disease and hunting, there were only 1,000 bighorn sheep in Montana. Now, there are over 5,000, thanks to constant work by wild sheep organizations and FWP.
However, the officials are always warning against exposure of wild sheep to domestic sheep, which are not affected by the bacteria, but many are carriers. For instance, a 2010 pneumonia outbreak killed over 600 sheep in western Montana. Bighorn sheep are found mainly in Montana, Idaho, eastern Washington and Oregon, Utah and Arizona.