Trophy description - Save all the Wild Waste locals.

Trophy - Bronze

This trophy is unlocked in Act IV, Curtain I. After progressing through the canyons area at the start of the level you will arrive at an old western town. The first locals are located in the second scene of the town on the top of the right hand side building. Once you make your way up investigate the wooden structure with Pikarina by pressing R2. The next locals are in the prison on the left hand side building. You will need to body slam from the roof with R1 and then press R2 on the local that remains in the prison. The final set of locals are in the scene with the overturned horse and carriage. Climb the left hand side structure and investigate the wooden water reservoir at the top. The trophy will unlock once you investigate the structure with Pikarina by pressing R2.

It's worth noting that the trophy is cumulative, meaning that you don't need to save all locals in the one playthrough of the level. See the below video by Wozamil for the exact locations of the Wild Waste locals in the level.