Great Northern Engineering Drawing: Abutment 1 - Revision, Bridge 20 - Undercrossing, north of Clayton, Washington, Line Segment 376, Milepost 34.37. Sheet 270 - 4691 - 5A, 1938.

Great Northern Engineering Drawing: Bar List, Bridge 20 - Undercrossing, north of Clayton, Washington, Line Segment 376, Milepost 34.37. Sheet 270 - 4691 - 10, undated.

Great Northern Engineering Drawing: Deck Slabs, Bridge 20 - Undercrossing, north of Clayton, Washington, Line Segment 376, Milepost 34.37. Sheet 270 - 4691 - 9, undated.

Great Northern Engineering Drawing: Drainage Details, Bridge 20 - Undercrossing, north of Clayton, Washington, Line Segment 376, Milepost 34.37. Sheet 270 - 4691 - 11, undated.

Great Northern Engineering Drawing: Girder Spans, Bridge 20 - Undercrossing, north of Clayton, Washington, Line Segment 376, Milepost 34.37. Sheet 270 - 4691 - 7, undated.

Great Northern Engineering Drawing: Layout, Bridge 20 - Undercrossing, north of Clayton, Washington, Line Segment 376, Milepost 34.37. Sheet 270 - 4691 - 3, 1938.

Great Northern Engineering Drawing: Miscellaneous Steel Details, Bridge 20 - Undercrossing, north of Clayton, Washington, Line Segment 376, Milepost 34.37. Sheet 270 - 4691 - 8, undated.