Here’s Where To Find Every Skull in Halo: Combat Evolved for The Master Chief Collection

Halo (Skulltaker Halo: CE: Boom Achievement)

The second skull in this mission can be located in the same area where you’re supposed to fight off waves of the Covenant while protecting the human marines. This is when a Warthog will be dropped off for your disposal, hop in the Warthog and yet again, head to the right. If you’ve gone into the underground tunnel, you’ve gone too far. Get yourself onto the ledge of the canyon and continue to pass two trees. Almost directly after the second tree is the Boom skull.