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.

Police are looking for Michael Paul Brown, 45, after four people were shot and killed in The Owl Bar in the small town of Anaconda, Montana.