US Bridges

County Road 121 over S.Fk Williams Fork River

Fair

Rio Blanco County, Colorado · 0.42 MI S of Moff CO Line · Structure no. RIOB-121-00.50

Built
1984
41 years old
Condition
Fair
inspected September 2024
Type
Girder and Floorbeam System
Steel
Length
50 ft
1 main span
Daily traffic
32
2023 count
Owner
County
County Highway Agency

About this bridge

County Road 121 over S.Fk Williams Fork River is a steel girder and floorbeam system carrying County Road 121 over S.Fk Williams Fork River in Rio Blanco County, Colorado. It was built in 1984, so it is 41 years old, younger than the Colorado average of 42.2 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 32 vehicles a day, projected to reach 38 by 2043. The structure is 50 ft (15.3 m) long and 16 ft wide. If it were closed, the detour would be 100 mi (161 km).

Location

Open in Google Maps
CarriesCounty Road 121
CrossesS.Fk Williams Fork River
Location0.42 MI S of Moff CO Line
RouteCounty Highway 0
CountyRio Blanco County
StateColorado
Coordinates40.21542, -107.4438
Functional classRural Local

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry8: Equal to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating11.4 US tons
Inventory rating6.8 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckCorrugated steel
Main spans1
Design loadHS 20
Structure length50 ft (15.3 m)
Longest span49 ft (14.8 m)
Deck width16 ft (4.9 m)
Roadway width16 ft (4.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic32 (2023)
Projected traffic38 by 2043
Trucks0%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed100 mi (161 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 County Road 121 over S.Fk Williams Fork River built?

It was built in 1984, making it 41 years old in 2025.

What condition is County Road 121 over S.Fk Williams Fork 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 September 2024.

How much traffic does County Road 121 over S.Fk Williams Fork River carry?

About 32 vehicles per day (2023 count).

How long is County Road 121 over S.Fk Williams Fork River?

The structure is 50 ft (15.3 m) long with a longest span of 49 ft (14.8 m) and a deck 16 ft wide.

Who owns County Road 121 over S.Fk Williams Fork River?

It is owned by the County Highway Agency.