1 vote

J Avenue Overpass


Oblique View

From the northeast side.

Photo taken by J.R. Manning

BH Photo #109484



Bridge is likely built using a former Chicago & North Western Railway span, which has been reconstructed for road use.


Pony truss bridge over Union Pacific Railroad on J Avenue
Boone County, Iowa
Open to traffic
Built 1900
- Chicago & North Western Railway (CNW)
- Union Pacific Railroad (UP)
Riveted double-intersection Warren pony truss
Length of largest span: 69.9 ft.
Total length: 140.1 ft.
Deck width: 18.4 ft.
Also called
Hump Bridge
Approximate latitude, longitude
+42.05213, -93.98946   (decimal degrees)
42°03'08" N, 93°59'22" W   (degrees°minutes'seconds")
Approximate UTM coordinates
15/418121/4656038 (zone/easting/northing)
Quadrangle map:
Boone West
Land survey
T. 84 N., R. 27 W., Sec. 27
Inventory numbers
IA 77860 (Iowa bridge number)
BH 12908 (Bridgehunter.com ID)
Inspection (as of 05/2010)
Deck condition rating: Poor (4 out of 9)
Superstructure condition rating: Serious (3 out of 9)
Substructure condition rating: Poor (4 out of 9)
Appraisal: Structurally deficient
Sufficiency rating: 14.6 (out of 100)
Average daily traffic (as of 2007)

Update Log 

  • February 25, 2017: New photos from Daniel Barnes
  • October 11, 2016: New photos from John Marvig
  • June 2, 2015: New photos from Kevin Skow
  • May 15, 2014: New photos from Lee Smith
  • March 28, 2013: New photos from John Marvig
  • September 2, 2011: Updated by Luke Harden: Added alternate name
  • February 19, 2010: Updated by J.R. Manning: Updated Location

Related Bridges 


  • J.R. Manning - thekitchenguy [at] sbcglobal [dot] net
  • Luke
  • John Marvig - marvigj27 [at] gmail [dot] com
  • Lee Smith - ljsmith_32 [at] hotmail [dot] com
  • Kevin Skow - weatherbum [at] hotmail [dot] com
  • Daniel Barnes


J Avenue Bridge
Posted May 6, 2013, by C J Johnson (108stitchesiowa [at] netzoola [dot] com)

Union Pacific trains roar many times daily under this bridge at well over 50+ mph before crossing the new concrete Kate Shelley High Bridge completed East of this bridge. I believe that this bridge is sometimes referred to as the "Humpback Bridge".

Photo taken Winter 2013.

UPRR Bridge
Posted July 16, 2007, by Lugnuts (thekitchenguy [at] sbcglobal [dot] net)

This bridge is located off 200th Street on L Road, a dead-end road, and provides the only access over the double-tracked Union Pacific mainline that some proptery owners have. The fence posts along the road leading away from the bridge appear to have been cut from a shoe tree.

This is a virtual twin to the pony truss bridge listed as #77840. The twin tracks shown continue west, cross the Des Moines River on the Kate Shelly Bridge (see Truss Bridge #77850 for more about the Kate Shelly Bridge) then curves to the southwest and goes under #77840.

The bridge is all wood timbered and wood decked. It has little trafic but appears to be well maintained.

Webmaster's note: The photos that were here have been incorporated into the main site.