Treasures of ECHO Madre

First things first, you'll get this mission from Pickle in Outlands Canyon after completing 'Intelligences of an Artificial Persuasion'. He'll tell you about a treasure map and hand you a shovel. Head to the waypoint marked on your screen.

When you arrive, you won't find a map lying around. Instead, you'll need to talk to Timber Logwood, an NPC nearby. He'll tell you he saw the map but flushed it down the toilet. Typical.

Pickle, being the greedy guy he is, sends you to the dump to find the map. Make your way to the new waypoint. Once you're there, search the highlighted areas. Keep an eye out, because instead of a map, a Thresher will pop out! These guys are like underground squids, so try to keep your distance when they resurface.

After you defeat the Thresher, it'll drop the map. The search area is pretty large, but you're looking for an 'X' that marks the spot. You'll find the X across a gap, made of two metal beams, near a ledge. Unfortunately, boulders are blocking the way. You'll need to head back across the gap to find some explosives.

Follow the waypoint to find the explosives. They're all together in a building on the right side. Grab all three.

Head back to the boulders blocking the treasure spot and plant the explosives. Boom! An explosion will clear the path.

Enter the newly opened area and go inside the bunker. Rabid Adams will appear. Take him down, grab the ECHO he drops, and then feel free to loot the place.

Once you're done, head back to Pickle to turn in the mission.