The railroad Pulga Bridge is located on the Union Pacific Railroad's (originally Western Pacific Railroad's) Feather River Route through the Sierra Nevada in northeastern California, connecting the Sacramento Valley to Salt Lake City via the Feather River valley. The bridge is part of the WP's eastward climb to its summit at Beckwourth Pass while maintaining the railroad's overall 1.0 percent (compensated) grade, making it the easiest railroad route over the Sierra Nevada.