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.

( 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.

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.