Interactive Red Dead Redemption 2 Map

This is the Wide Blade Knife location.

You will find the Wide Blade Knife on a dead body in a tunnel that is blocked off by rocks. You need to push the plunger near the entrance to set off the TNT. This will open up an area behind the rocks where you will find a body with the Wide Blade Knife sticking out of it's back and the Miner's Hat laying beside it.