Follow the waypoint locator to find the home of the 3 survivors. Take them to the next mission marker, then leave the place to clear the task. After this, there will be 3 rucksacks left by the survivors in the previous meeting area. Feel free to take them back to your home base.
Sometime after, the Wilkersons will reward you by giving you a M60 machine gun. You will also acquire the Radio Assistance Option "Sharpshooting".