3 votes

Tongue River Bridge


Through, View to North

Photo taken by Martha Carver in August 2014


BH Photo #305602



The bridge was located in the town of Monarch, a coal company town. The Wyoming Coal Mining Company opened a mine there in 1903 which continued to produce coal until the mine closed in 1953. By 1910 the area was a thriving town with a population of about 1000 people, and the mine employed about 400 people. Peak employment later reached about 800. Most workers lived in the town in housing provided by the coal company. Other buildings included a school, various commercial buildings such as a commissary as well as two churches and a cemetery. As of 2014, the Catholic Church (now a private residence), the cemetery, the mine foreman’s house, a few livestock structures, a water tower, and the bridge remain. Wyoming has included the site on a scenic byway, the Black Diamond Trail, and an interpretative marker is located near the bridge (although it does not mention the bridge). For information on the Trail, see http://wyoshpo.state.wy.us/MM/Byway.aspx.

According to Black Diamonds of Sheridan written by Stanley A. Kuzara in 1977 (pages 148-168), the mine was located about a mile from the tipple, which was located at the railroad, and the two were “connected by an electric trolley line over which the mine cars are hauled by motors.” Thus, the west side of the bridge carried vehicular traffic and the east side carried a rail line leading to the tipple (see sketch map from Kuzara’s book). This arrangement resulted in a bimodal bridge.

This bimodal bridge reflects an unusual design. It has three panels with the two outer ones featuring outriggers. The central panel serves double duty, carrying both lanes, and is a heavier design featuring a different composition.


Pony truss bridge over Tongue River on Cn3-110
Sheridan County, Wyoming
Open to traffic
Built 1903
Warren pony truss
Length of largest span: 53.5 ft.
Total length: 97.1 ft.
Deck width: 15.1 ft.
Also called
Monarch Bridge
Approximate latitude, longitude
+44.90236, -107.03085   (decimal degrees)
44°54'08" N, 107°01'51" W   (degrees°minutes'seconds")
Approximate UTM coordinates
13/339666/4974110 (zone/easting/northing)
Quadrangle map:
Average daily traffic (as of 2017)
Inventory numbers
WY MGG (Wyoming bridge identifier)
BH 47781 (Bridgehunter.com ID)
Inspection report (as of May 2018)
Overall condition: Poor
Superstructure condition rating: Serious (3 out of 9)
Substructure condition rating: Serious (3 out of 9)
Deck condition rating: Good (7 out of 9)
Sufficiency rating: 17.6 (out of 100)
View more at BridgeReports.com

Update Log 

  • October 22, 2014: New photos from Martha Carver
  • January 21, 2011: Added by J.P.


  • J.P. - wildcatjon2000 [at] gmail [dot] com
  • Martha Carver - martha_carver [at] bellsouth [dot] net


Tongue River Bridge
Posted October 23, 2014, by Nathan Holth (webmaster [at] historicbridges [dot] org)

Very interesting bridge. I don't know much about Wyoming aside from its striking lack of historic truss bridges. I would hope that this early rivet-connected truss bridge with the unusual multi-function three truss line design would be considered eligible for the National Register of Historic Places and a preservation plan is in place for the bridge.