US Bridges

US 85 over Robbers Roost Creek

Fair

Niobrara County, Wyoming · Mule Creek Jct-Newcastle · Structure no. JOH

Built
1992
33 years old
Condition
Fair
inspected June 2024
Type
Culvert
Concrete
Length
22 ft
2 main spans
Daily traffic
1,084
2024 count
Owner
State
State Highway Agency

About this bridge

US 85 over Robbers Roost Creek is a concrete culvert carrying US 85 over Robbers Roost Creek in Niobrara County, Wyoming. It was built in 1992, so it is 33 years old, younger 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 1,084 vehicles a day, roughly 15% of them trucks, projected to reach 1,518 by 2043. The structure is 22 ft (6.6 m) long. If it were closed, the detour would be 98.8 mi (159 km).

CarriesUS 85
CrossesRobbers Roost Creek
LocationMule Creek Jct-Newcastle
RouteU.S. Route 85
StateWyoming
Coordinates43.46978, -104.20469
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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating36 US tons
Inventory rating36 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans2
Design loadHS 20
Structure length22 ft (6.6 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,084 (2024)
Projected traffic1,518 by 2043
Trucks15%
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 statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was US 85 over Robbers Roost Creek built?

It was built in 1992, making it 33 years old in 2025.

What condition is US 85 over Robbers Roost Creek 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 June 2024.

How much traffic does US 85 over Robbers Roost Creek carry?

About 1,084 vehicles per day (2024 count), of which roughly 15% are trucks.

How long is US 85 over Robbers Roost Creek?

The structure is 22 ft (6.6 m) long with a longest span of 10 ft (3 m).

Who owns US 85 over Robbers Roost Creek?

It is owned by the State Highway Agency.