This spoiler free page of the guide to The Last of Us 2 has information about the locations of all safes in the Jackson chapter. In addition to the locations of the safes, we present solutions to puzzles in which you find the right safe combination and inform about the contents of the safes.
List of safes in the Jackson chapter
There is only 1 safe in the Jackson chapter:
1st safe - the Patrol stage
Safe from the Patrol stage
The safe can be found in the room you reach shortly after Ellie and Dina decide to wear masks. It is a building that you can access from the roof by running on a large semi-trailer truck.
Good Boy Combo document is on the desk to the right of the safe. Its contents include a hint on the combination that opens the safe.
Find the board in the same room with pictures of employees of the month. Check out the photo of the dog, specifically the information about the month and year visible above the photo.
The date is a combination to the safe -month/day/year. The safe's code is 07-20-13.
Inside the safe, you will find scrap metal and supplements.