Northern Pacific Engineering Drawing: Detail of Abutment/Piers, Bridge 233 - Prickly Pear Creek, East Helena, Montana, Line Segment 041, Milepost 233.7. Sheet 1068 - 43, undated.

Northern Pacific Engineering Drawing: General Plan, Bridge 233 - Prickly Pear Creek, East Helena, Montana, Line Segment 041, Milepost 233.7. Sheet 1068 - 43, 1928.

Plat Map of Northern Pacific facilities at East Helena, Montana, November 16, 1916, Sheet Number 1, Line Segment 712, showing the East Helena yard, smelter trackage, Great Northern mainline.

Plat Map of Northern Pacific facilities at East Helena, Montana, November 16, 1916, Sheet Number 2, Line Segment 712, showing the East Helena yard, smelter trackage.

Plat Map of Northern Pacific facilities at East Helena, Montana, April 10, 1941, Sheet Number 1, Line Segment 712, showing the East Helena yard, McClellan spur.

Plat Map of Northern Pacific facilities at East Helena, Montana, April 10, 1941, Sheet Number 2, Line Segment 712, showing the East Helena yard, McClellan spur.

Plat Map of Northern Pacific facilities at East Helena, Montana, April 10, 1941, Sheet Number 4, Line Segment 712, showing the East Helena yard, Great Northern interchange.

Plat Map of Northern Pacific facilities at East Helena, Montana, April 10, 1941, Sheet Number 3, Line Segment 712, showing the East Helena yard, smelter spur.