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.

Officers are "unrelenting in their pursuit, working around the clock" to find him, Montana Gov. Greg Gianforte stressed at a news conference on Tuesday. "Rest assured, our brave men and women of law enforcement aren’t giving up."

( NewsNation) — Montana Gov. Greg Gianforte and Attorney General Austin Knudsen will hold a news conference Tuesday as a search for the suspect in a deadly bar shooting moves into its sixth day. Michael Paul Brown, 45, a U.S. Army veteran, is accused of killing four people at the Owl Bar in Anaconda, Montana, on Friday.