Authorities say there are signs Michael Paul Brown has been in a mountainous area since he allegedly shot and killed four people in an Anaconda bar on Friday.

As the search for Michael Paul Brown continued, Montana Gov. Greg Gianforte signed an executive order freeing up more resources for local law enforcement.

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.