GREAT FALLS – State wildlife officials have killed four bighorn sheep after they mixed with domestic sheep south of Cascade.

The four female sheep were part of a group of 25 bighorns that were moved in December from the Missouri River Breaks to a hunting district between Cascade and Helena.

By mid-January, the four ewes were found 20 miles away from their release site and mixing with domestic sheep. The sheep were killed Wednesday.

Fish, Wildlife and Parks policy calls for killing bighorn sheep that mix with domestic sheep to avoid the potential transfer of pathogens that can cause pneumonia in wild sheep.

Region 4 Supervisor Gary Bertelloti says pneumonia can cause a large die-off in a bighorn herd and, in some cases, the herds don’t recover.

The meat, which is safe for human consumption, was donated to a food bank.