Horde Killer Completion At 98%?

So you think you finished all horde areas, but still have 2% left? Well, here's an easy fix.

Credits goes to the top comment in this thread:
https://www.reddit.com/r/DaysGone/comments/bl9vyf/horde_killer_storyline_not_100/

Yeah so basically, there's this little area north of the Horse Lake Nero Checkpoint that you probably haven't visited, because to be honest there's really nothing interesting there at least by first glance.

To the left, you have the horde gathering areas and to the right is a bandit camp.