A manhunt is intensifying for the former U.S. Army soldier who's been at large for days after allegedly gunning down four people at a Montana bar.Michael Paul Brown, 45, is suspected of opening fire on Friday morning at The Owl Bar in Anaconda,

Stymied by treacherous terrain and untamed wilderness, authorities are struggling to find an Army veteran suspected of killing four people at a Montana bar. But the difficult landscape isn’t the only challenge.

Four people were killed in a shooting at a bar in Anaconda, Montana, on Friday, authorities said. A suspect is at large.