US Bridges

US 20 over Big Horn River

Fair

Hot Springs County, Wyoming · Shoshoni - Thermopolis · Structure no. BRM

Built
1957
68 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
313 ft
4 main spans
Daily traffic
2,711
2024 count
Owner
State
State Highway Agency

About this bridge

US 20 over Big Horn River is a steel continuous stringer/multi-beam or girder carrying US 20 over Big Horn River in Hot Springs County, Wyoming. It was built in 1957, so it is 68 years old, older than the Wyoming average of 48.4 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 2,711 vehicles a day, roughly 13% of them trucks, projected to reach 3,795 by 2043. The structure is 313 ft (95.4 m) long and 35 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesUS 20
CrossesBig Horn River
LocationShoshoni - Thermopolis
RouteU.S. Route 20
CountyHot Springs County
StateWyoming
Coordinates43.59224, -108.21362
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating67 US tons
Inventory rating40 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length313 ft (95.4 m)
Longest span84 ft (25.6 m)
Deck width35 ft (10.7 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,711 (2024)
Projected traffic3,795 by 2043
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was US 20 over Big Horn River built?

It was built in 1957, making it 68 years old in 2025.

What condition is US 20 over Big Horn River in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in April 2024.

How much traffic does US 20 over Big Horn River carry?

About 2,711 vehicles per day (2024 count), of which roughly 13% are trucks.

How long is US 20 over Big Horn River?

The structure is 313 ft (95.4 m) long with a longest span of 84 ft (25.6 m) and a deck 35 ft wide.

Who owns US 20 over Big Horn River?

It is owned by the State Highway Agency.