Highway Exit: Family Photograph (Artifact)
Look inside the mobile home in the middle of the Highway.
Highway Exit: Katerina Perich 000149 (Firefly Pendant)
After heading down the highway ramp, go left and look behind the first car.
Highway Exit: Note to Wife (Artifact)
Inside the bus station, look in the suitcases near the ticket machines.
Highway Exit: Precipitate (Comic)
In the toilets near the exit to the bus station.
Highway Exit: Tools
In the large tent in the middle of the bus depot area.
Highway Exit: Nicole Hoo 000201 (Firefly Pendant)
Past the tents in the bus depot, shoot or brick/bottle the Firefly Pendant from the set of lights.
Highway Exit: Salt Lake Q.Z. Map (Artifact)
In the small tent in the corner of the bus depot area next to a collapsed tent.
Underground Tunnel: Natalie Hoo 000202 (Firefly Pendant)
Behind the bus on the ramp down to the tunnel.
Underground Tunnel: Bomb: Shrapnel (Training Manual)
In the tunnel, on top of a truck in the area with two Bloaters.
Underground Tunnel: Catalysis (Comic)
After swimming through the barricade, climb along the vents next to where you drop the ladder.
Underground Tunnel: Shiv Door
After boosting Ellie over the fence to open the gate, follow the next tunnel to the right instead of to the left.