Many manhunts end quickly, but the man accused of killing four people in rural Montana appears to have disappeared into the kind of wilderness that helps elude pursuers.

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."

Four people were killed in a shooting at a bar in Anaconda, Montana, on Friday, authorities said. A suspect is at large.