Soviet Installation - Collectibles on the Path to the Research Base

Shoot 2 or 3 climbing arrows into the wooden wall near the campsite and use them to climb onto the ledge above.

Here you'll find a document (26/26), Contact from the Radio Calls series, and a strongbox (14/14) containing a HEAVY PISTOL PART (4/4).

Continue up the path to discover an Explorer Satchel (6/6) lying near a dead body. This reveals the locations of the last 2 survival caches (20/21 and 21/21) on your map. The first of these caches is buried very close to the satchel.

Return down the hill to where you found the last document, drop onto the small snowy ledge below on the left...

...and dig up the other cache. If you followed this walkthrough it will be the last one.

If you missed the survival cache (5/21) buried behind the SUPPLY SHACK earlier, it will be marked on your map now. Either drop down from the ledge where you found the previous cache, or climb back up, stand near the rope-wrapped post, and use a rope arrow to create a zip line so you can slide down. Retrieve the cache. Then, if you like, stop at the campfire again to examine/equip the HEAVY PISTOL.