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.

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,

( NewsNation) — Montana officials said the search for the suspect in a deadly bar shooting is expanding as it enters a sixth day. Officials did not give specifics on where the search has expanded but said there are several local, state and federal teams taking part in efforts.