Northern Pacific Engineering Drawing: Proposed Bridge west Boundary Crossing, Bridge 64 (48) - Union Pacific Railroad, west of Irwin, Washington, Line Segment 045, Milepost 64.53, undated.

Northern Pacific Engineering Drawing: Proposed Bridge Westbound Crossing, Bridge 64 - Union Pacific Railroad, west of Irwin, Washington, Line Segment 045, Milepost 64.53. Sheet 447 - 18, undated.