The Salt Lake Q.Z. map is an optional artifact in the triage area outside the Salt Lake City bus station. Go to the small tent in the far corner where the workbench is and take it from the table on the left.
A map of the Salt Lake City quarantine zone, the abandoned military area Joel and Ellie cross on their way toward the Fireflies' hospital.
Bomb: Shrapnel
Bomb: Shrapnel is the last training manual, on top of a box truck in the underground tunnel of Bus Depot. It doubles the blast radius of nail bombs.
Catalysis
Catalysis, issue 13 of Savage Starlight, sits at the end of the ventilation ducting that runs along the underground tunnel in Bus Depot.
Family photograph
The Family photograph is an optional artifact in an overgrown camper on the highway at the start of Bus Depot. Before you leave the highway, climb into the camper in the middle of the road and check the dining table on the left.
Natalie Hoo's Firefly Pendant
Natalie Hoo's Firefly pendant lies in a corner behind a city bus on the ramp down to the underground tunnel in Bus Depot. It belonged to Natalie Hoo.