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."

The manhunt in Montana is on day 5 for a former U.S. Army soldier on the run days after he allegedly shot and killed four at a local bar in the southwest part of the Treasure State.

An "armed and dangerous" gunman is still on the loose in Anaconda, Montana as of Saturday after killing four people on Friday

The suspect in the quadruple killings, 45-year-old Michael Brown, remained a fugitive, officials told USA TODAY on Aug. 4.

The search for suspect Michael Paul Brown is still underway as law enforcement ramps up efforts to track him down.

It’s still unclear why Michael Paul Brown allegedly killed four people at the bar around 10:30 a.m. Friday before fleeing in his underwear.