Siberian Wilderness - Collectibles (Part 1)

From the sapling you just stripped for hardwood, continue to the right and down the slope, more or less following the southwest edge of the map...

...until you come to a length of tree trunk lying across the path.

Look to the left to spot a document (1/6) sitting on a rock ledge.

Use Survival Instinct If you're having trouble spotting it in the dark. Climb up and examine the document, The Prize Awaits from the Voices of Invasion series, for XP and primer in the Mongolian written language.

Hop down off the ledge and climb back up near the fallen log.

Survival Instinct reveals a rope-wrapped wooden barrier and a leather backpack sitting on a nearby ledge.

If you approach the barrier, you'll discover Lara needs Rope Arrows to get through. You won't get this upgrade for quite some time, so make a note to return here later.

Climb up next to the backpack and examine it by pressing X.

This Explorer Satchel reveals the location of nearby coin caches, documents, and caves on your map. Once you've found it, the satchel itself is indicated by a skull icon on the map.

Just downhill from the ledge with the satchel is another cave.

This one is blocked by an impact barrier. Again, you don't have the necessary gear to get through, so plan to return later in the game when you do.