3 votes

WSOR - Wisconsin River Bridge (Merrimac)


Oblique View Looking North

Taken from a state-owned "Wayside" park along the east shore of the Wisconsin River.

Photo taken by J.R. Manning in October 2007

BH Photo #141113


Street Views 


From East to West:

Span A-64' Deck Girder, built 1903
Span B-103' Quadrangular Deck Truss, shortened 1930
Span C-48' Deck Girder, Built 1930
Spans D through M-48' Deck Girders, Built 1895 on Steel Towers
Span N-79' Deck Girder, Built 1930
Span O-107' Quadrangular Deck Truss, Built 1895
Span P-77' Quadrangular Deck Truss, Built 1895 and shortened 1930
Span Q-118' Quadrangular Deck Truss, Built 1903
Span R-152' Quadrangular Deck Truss, Built 1903
Span S1 and S2-205' Center Pivot Deck Truss Swing Bridge, Built 1903
Span T and U-122' Quadrangular Deck Trusses, Built 1903

The 1895 spans were built by Lassig Bridge & Iron Works; while the 1903 spans and 1930 modification were done by American Bridge Company

Chicago & Northwestern Structure No. 334 

Written by J.R. Manning

The Wisconsin & Southern Railroad owns this 22 span, combination deck/plate girder deck truss bridge that crosses Lake Wisconsin (part of the Wisconsin River) between Merrimac and Okee. The span is 1,729 feet in length and is a part of the historic mainline that ran from Madison to Sparta on the old Chicago & Northwestern Railway. (The span is parallel to the Colsac III ferry.)

The same right-of-way crosses several other historic bridges that are documented here, including the Baraboo Street Bridge, Goette Road Bridge, Highway 136 CNW Bridge, Chestnut Street Bridge, Mill Street Bridge and the Viaduct Road Bridge. (The Viaduct Road bridge actually shows two build dates because it was widened in 1896 to accommodate a second track. The second track was removed several years ago.)

Bridge 334 was built with a single track, however, the span was modified to have a second main line track added, using a gauntlet bridge, and some of the piers were originally poured with the intention of adding a second track. The second track was never built.

A tip o' the hat to Ken Lucht of the Wisconsin & Southern Railroad for his help in expanding our knowledge and understanding of this historic structure!

Follow the links below to see a Wisconsin & Southern train crossing the bridge and to see the Circus World Museum's 2000 Circus Train crossing the bridge.)


Deck truss bridge over Lake Wisconsin on Wisconsin & Southern Railroad in Merrimac
Merrimac, Sauk County, Wisconsin, and Columbia County, Wisconsin
Open to traffic
Built 1895 and 1903, Modified 1930
- American Bridge Co. of New York
- Lassig Bridge & Iron Works of Chicago, Illinois
- Chicago & North Western Railway (CNW)
- Wisconsin & Southern Railroad (WSOR)
Combination, open deck truss and plate girder deck truss with one swing span that is no longer functional
Length of largest span: 200.0 ft.
Total length: 1,729.0 ft.
Also called
CNW - Bridge #334
CNW - Wisconsin River Bridge (Merrimac)
Approximate latitude, longitude
+43.37060, -89.62228   (decimal degrees)
43°22'14" N, 89°37'20" W   (degrees°minutes'seconds")
Approximate UTM coordinates
16/287547/4805310 (zone/easting/northing)
Quadrangle map:
Inventory number
BH 42721 (Bridgehunter.com ID)

Update Log 

  • November 29, 2017: New photo from David Shedlock
  • December 23, 2015: New photo from Charles Kuehn
  • November 18, 2015: Updated by John Marvig: added detailed build dates
  • April 4, 2015: Updated by John Marvig: Added information
  • June 17, 2014: New photos from John Marvig
  • June 23, 2013: New Street View added by Dave King
  • June 3, 2012: New photo from Max Koehn
  • January 12, 2011: New photos from Eric Hanson
  • November 22, 2009: Updated by J.R. Manning: Updated Railroad Data
  • June 15, 2009: Essay added by J.R. Manning
  • June 6, 2009: Added by J.R. Manning

Related Bridges 


  • J.R. Manning - thekitchenguy [at] sbcglobal [dot] net
  • Wisconsin & Southern Railroad - A photo of a WSOR train crossing the Merrimac Bridge
  • Trainweb - Photos the Circus World Museum circus train, hauling the museum's extensive collection of wagons, to Milwaukee for the circus parade. Photos include the train crossing the Merrimac Bridge.
  • Eric Hanson
  • Max Koehn - mkoehn45 [at] gmail [dot] com
  • Dave King - DKinghawkfan [at] hotmail [dot] com
  • Douglas Butler
  • John Marvig - marvigj27 [at] gmail [dot] com
  • Charles Kuehn
  • David Shedlock


WSOR - Wisconsin River Bridge (Merrimac)
Posted February 23, 2021, by John Marvig (marvigj27 [at] gmail [dot] com)

Replacement of significant portions of this bridge is scheduled to begin in 2021. From what I understand, Spans A, D-M, Q and R will be replaced; along with a total deck replacement and substructure replacements. My goal is to get here before the ice on the lake melts to completely document every span, but so far, the weather has not cooperated.

WSOR - Wisconsin River Bridge (Merrimac)
Posted June 7, 2020, by Glenn Gierzycki (graz [at] gbis [dot] com)

The bridge was originally built with a swing span to allow steamboats to go through. I have seen a picture of the span open with a boat moving through. My guess is it was not used often as the Wisconsin River was not very navigable due to shallow depths and shifting sand bars. The bridge has been rebuilt several times. The bridge was originally higher but the water level rose with the building of the dam at Prairie du Sac. The bridge was built for one track but when the line between Madison and Baraboo was doubled tracked, the bridge hosted a gauntlet track. This type of track was built on the bridge but never connected with the original track. The two tracks ran parallel to each other on the bridge but were not connected by switches. Train traffic on the bridge was controlled by two-story control towers at each end. I've seen pictures of those also.

WSOR - Wisconsin River Bridge (Merrimac)
Posted April 3, 2018, by Dane (t [dot] g [dot] lambini [at] gmail [dot] com)

Does anyone happen to know what the clearance is under Spans D through M-48' Deck Girders? Wondering if my Hobiecat sailboat mast (26'6") would clear. Thanks.

WSOR - Wisconsin River Bridge (Merrimac)
Posted February 5, 2016, by Greg Stangl (profotoguy [at] hotmail [dot] com)

Does anyone know anything about the wrecked and rusted cars that are on either side of this bridge at the waterline. There must be 5-10 cars there and they are covered with dirt.. they are on and at the waterline. How did they get there? Was it a train wreck of some kind? Thanks.. Greg

WSOR - Wisconsin River Bridge (Merrimac)
Posted April 4, 2015, by John Marvig (marvigj27 [at] gmail [dot] com)

This bridge, along with all other bridges on the former C&NW mainline from Reedsburg to Madison are now owned by the State of Wisconsin, however are continuing to be operated by Wisconsin & Southern

WSOR Wisconsin River Bridge (Merrimac)
Posted December 13, 2013, by John Marvig (johnmarvig [at] chaska [dot] net)

The predecessor was built in 1878 by Leighton Bridge & Iron Works, who completed two other known projects for the C&NW in 1880 (High Bridge in Eau Claire, WI and Redstone Bridge in New Ulm, Minnesota). This bridge featured a lattice deck truss design with a through truss main span. It did not have a swing bridge, although it had a long main span.

CNW Bridge 334 Wisconsin River bridge at Merrimac
Posted February 26, 2013, by Ed Hollowell (erhollowell [at] aol [dot] com)

"If you don't believe me,..."

I believe you. The same type geniuses are building the 'Bullet train' in California for $100B. Nothing ever changes.

Also look up the Tennessee-Tom Bigby Canal. America has always had a taste for pork.

CNW Bridge 334 Wisconsin River bridge at Merrimac
Posted February 25, 2013, by Robert Thompson



The Federal Government took over the Green Bay and Mississippi Canal Company in 1870 and ran the entire system until it abandoned the Wisconsin River and Upper Fox River portion in 1951. The Lower Fox River section continued to be operated by the Army Corps of Engineers until the 1980's.

CNW Bridge 334 Wisconsin River bridge at Merrimac
Posted February 25, 2013, by Robert Thompson

1) The swing span is the third span out from the northwest shore. Just checked it out on Yahoo Maps.

2) Quite true "The Wisconsin was never deep enough to handle commercial boat traffic". But that did not prevent the Federal Government from spending millions of dollars per year to maintain the Fox-Wisconsin waterway.

If you don't believe me, take a look at the dam at Prairie du Sac. You will see a large, now disused navigation lock at the west end. If there was no navigation in the river, why was it put there?

CNW Bridge 334 Wisconsin River bridge at Merrimac
Posted February 25, 2013, by Johann (johnjohn [at] hmail [dot] com)

Dude, you have a couple of discrepancies regarding this bridge. It is owned by the Union Pacific and LEASED to the WSOR. This is a FIXED bridge-no moving spans. The center span was made beefier to handle the entire weight of a train on the entire formerly double tracked bridge. The reason the bottom beam is painted yellow is so the drunk boaters, on Lake Wisconsin, don't hit it. They do anyway. Before the Wisconsin River was dammed up at Prairie du Sac, the water level was 15 feet lower and any traffic could pass beneath the center span. The Wisconsin was never deep enough to handle commercial boat traffic. You should ask about the Great Railroad Tie hiest from this line. LOL!

CNW Bridge 334 Wisconsin River bridge at Merrimac
Posted January 12, 2011, by Spanfan (susorcar [at] yahoo [dot] com)

A rather bizarre story about this bridge-years ago, a group of partyers was out boating on the river after dark & ran into the lattice section at high speed, decapitating the driver.