6 votes

Heart of Iowa Trail - Mousehole


Photo taken by Bill Dunbar

BH Photo #205751



Box culvert on Heart of Iowa Trail over 597th Avenue
Story County, Iowa
Open to to pedestrians and cyclists
Built 1912
- Charles Frederick Loweth of Cleveland, Ohio (MILW Chief Engineer)
- J. H. Prior (MILW Bridge Designer)
- Chicago, Milwaukee, St. Paul & Pacific Railroad (MILW; CMStP&P; CMStP)
- Rail-to-trail
Span length: 20.0 ft.
Total length: 20.0 ft.
Also called
Heart of Iowa Trail - 597th Avenue Overpass
MILW - 597th Avenue Overpass
MILW - Mousehole Bridge
Approximate latitude, longitude
+41.89697, -93.50848   (decimal degrees)
41°53'49" N, 93°30'31" W   (degrees°minutes'seconds")
Approximate UTM coordinates
15/457821/4638461 (zone/easting/northing)
Quadrangle map:
Inventory number
BH 49221 (Bridgehunter.com ID)

Update Log 

  • October 11, 2016: New photos from John Marvig
  • January 26, 2013: Updated by Luke Harden: Added category "Chicago, Milwaukee, St. Paul & Pacific Railroad"
  • July 27, 2011: Updated by Jason Smith: Made changes to the information in terms of location and bridge type
  • July 27, 2011: Updated by Luke Harden: changed design info


  • Luke
  • Jason Smith - flensburg [dot] bridgehunter [dot] av [at] googlemail [dot] com
  • John Marvig - marvigj27 [at] gmail [dot] com


597th Avenue Underpass
Posted August 23, 2011, by jim wilcox (jwsknk [at] iastate [dot] edu)

built around 1912 when the railroad relocated the line through that area making the cut to the right and filling to the left (west)

597th Avenue Underpass
Posted August 23, 2011, by jim wilcox (jwsknk [at] iastate [dot] edu)

also known locally and by Story County Conservation as "Mousehole"

597th avenue tunnel
Posted July 27, 2011, by Clark Vance (cvance [at] dogmail [dot] com)

People usually refer to them as tunnels if they are very long. I consider a tunnel to be cut through existing geology. This is probably more formally a rigid frame concrete bridge. Still, cool to honk the horn for the kids in all of us.

597th avenue tunnel
Posted July 27, 2011, by Luke Harden (lmharden [at] iastate [dot] edu)

I honestly don't know whether to classify it as a bridge or a tunnel.