Image: Bend Studio / PlayStationOfficial screenshot from Bend Studio / PlayStation.
The Old Sawmill Horde in Lost Lake is the biggest Horde in Days Gone, at 500 Swarmers. You have to clear it in I'll Save Some For You so the creosote truck can be filled. Stock up on fire and explosives before you ride in.
Walk the mill before you start and plan a loop. The yard has explosive barrels, loose log and plank piles and shelving you can drop. Tight gaps between the buildings funnel the Horde into a line.
Carry as many Molotovs and napalm Molotovs as you can craft, plus frag grenades or pipe bombs. Keep health and stamina cocktails ready, since stamina is what keeps you ahead of the pack. Save the LMG for the last hundred or so.
You do not have to finish it in one go. Hit it, run until it loses interest, and it heads back to the mill. Most Swarmers will not turn on you while they walk away, so you can shoot them in the back.
Once the Horde is gone, Deacon fills Rikki's truck with creosote. That truck is the bomb meant for the Wizard Island assault.
Anarchist Mine Horde
A 300-Swarmer Horde that only spawns during Just Doing My Job, the Diamond Lake job to clear an Anarchist camp and rescue Mitch Allen. It disappears for good once the mission ends, dead or not.
Bear Creek Hot Springs Horde
The Bear Creek Hot Springs Horde is a 50-Swarmer Horde Killer target in Belknap, north of Tucker's Hot Springs camp. It opens after We've All Done Things and pays well in Hot Springs Trust for its size.
Beasley Lake Horde
The Beasley Lake Horde is a 125-Swarmer Horde Killer target on Highway 97. It opens after For An Outlaw Biker and pays 4,000 XP plus Diamond Lake Trust.
Beaver Marsh Rest Stop Horde
The Beaver Marsh Rest Stop Horde is a 130-Swarmer Horde Killer target at a rest stop on Highway 97. It is one of the larger southern Hordes and pays 4,000 XP plus Diamond Lake Trust.