As the search for 45-year-old Michael Brown closes in on one week, authorities are continuing their efforts to locate the suspect in a mass shooting at the Owl

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.

The manhunt is focused on the wilderness area outside Anaconda, which local outdoor experts describe as particularly difficult to navigate.