Train Yard Second Visit - Mission: The Unlucky Ones (Part 1)

When you return to the Logging Camp after visiting the Gulag, you'll see an on-screen notification: Ally Nearby. Optional Mission Available. Enter the shack near the campfire...

...and talk to the Remnant General. He asks you to rescue two of his people who were captured.

If you accept the task, your map is updated with a green circle showing where to go first.

To reach the marked location, leave the cabin and head to the east. Then follow the curving path along the edge of the river...

...past an old truck near a fallen tree (there's some rifle ammo in the back of the truck)...

...until you come to a raised wooden structure. Climb up and follow it around...

...to a zip line anchored to a telephone pole near another abandoned truck.

Ride this line down to the base of the stone pillar in the middle of the river.

You'll notice a cave on the north side of the river, but the opening is blocked by a metal barrier that can only be destroyed with explosives. You'll have to return later once you have the proper gear.

There's also an herb bush on a rock ledge on the other side of the river. If you like, you can jump/swim across and pick it.

Climb the rough wall to the top of the stone pillar. (If you check your map now, you'll see the green Mission indicator has shifted to a point on the other side of the river.)

Jump across to the next section of climbable wall and climb onto the ledge above, where you'll find a container of herbs.

Stand near the rope-wrapped post and fire an arrow into the rope-wrapped beam ahead to create a line you can use to climb across to the next ledge.

From there, climb the cliff upward...

...then to the right until you reach the broad ledge at the top.