Quick walkthrough with coordinates of each of the locations of the clues and where to summon El Yeti.    If you have completed this before, including the Yeti ID’ing, you can just summon the Yeti to deal with him; collecting clues again isn’t required.

To speed up finding the spots to mark, you can turn on the Heatmap in the TacMap.

Camp Site: -20.7959 / -64.6258

At each location, make sure you wander around each area and get close to everything.  This will help to make sure you trigger the game’s internal “completion” of clue collecting.

Yeti Cave: -20.6620 / -65.4029

The cave will blend in; make sure to travel close to the rocks so the cave opening is easier to spot.

Enter the cave and explore the entire area, all levels inside!

Frozen Body on Cliff side: -20.5473 / -65.8779

This is a tricky one to spot.  Look for the orange-ish rope dangling down, which will help to speed up the hunt.     You do not have to go on the ledge with the body.  You can just ram your drone in extremely close, and check out the paper he is still holding, and such.

Bodies by Jeep: -20.4269 / -66.3492

Check around the Jeep and further west around the bodies.   Make sure the game registers you ‘found’ the clue.   Obvious at this location what the clue here is.

Crashed Plane: -19.3563 / -66.7910

Check the wreckage and area.  If you completed the other clues already, it’s just a short trip to summon El Yeti next.

Bloody hand rock to Summon the Yeti: -19.7418 / -66.6622

Right along the creek, you will find on the east side the blood-covered handprint rock.  Interact with the rock to summon El Yeti.    

From there, he will spawn in and attack you.  Kill him and spot him.    Leaving as much information out about this part to be a surprise.