WHERE IT STARTS:
The Treasure Hunt starts at SANTOS ESPINOSA DAM, LA JOYA.
THE NOTE SAYS:
"We understand all your requests completely. We will do whatever you need to make this dam a proper tribute to Yara's true Presidente.
I will fix the broken catwalk myself and my workers will repair the open sluices immediately.
And of course, all of us here are proud to give up our storeroom for your military supplies. Please meet me for your copy of the key.
Glory to Anton Castillo!
WHAT TO DO:
Written Guide below the Walkthrough Video
When you arrived here, you should have seen a worker fall down the gap in the dam walkway. He has the key.
You have to stop the water to get down there.
Go to the Control Room building on the other side of the dam. The doors are locked but you can shoot the lock on the other side from one of the windows.
Then climb on the roof and let yourself drop on the other side to get in.
Don't forget to pick up "The Phantom of La Joya #3" Hidden Stories on the Desk in the Control Room.
Then look at the instruction on the main control panel.
1 - Activate Sluice Control next to the calender
2 - Press the button on the side of hydraulic monitoring machines
3 - turn the pressure valve
4 - go back to the main console and hit the last button
Turn the pressure valve.
Press the button on the main console.
The water is now stopped and you can go get the keycard from the man.
Use the grapple or jump down to the dead man and pick up the card.
Use the grapple to get back up and open the door to get your reward.