Intel gathered in Koani has identified a truck depot as a hub of Santa Blanca's overland smuggling network in the province. Infiltrating the depot and copying its records will allow us to map the entire network from end to end.
To start this mission you need to complete Train Graveyard mission, and acquire major intel in Koani province.
Warning: This is a stealth mission so it fails if you're spotted by an enemy, you shoot an enemy with a weapon that isn't suppressed, or if an enemy discovers a corpse, e.t.c.
1. Enter the depot without being detected
Aearial view of the camp.

There is Santa Blanca truck guarded by just one guy parked on the road to the southwest. Steal it and use it to drive through the gates.

Park the truck behind the warehouse, next to the power generator - there are no patrolling guards there.

2. Locate the documents
Go to the warehouse from the back and sneak into the room where the documents are located.

3. Photograph the documents

4. Leave the depot undetected
Go back the same way you came, and use the same truck to leave the depot.

5. Mission Complete
The records obtained from the cartel truck depot will allow us to track every shipment the cartel sends across the border. We'll be able to target shipments at will, seizing the drugs at their destination along with their buyers.