US Bridges

County Road 42 over Fossil Creek Res. Inlet

Fair

Larimer County, Colorado · Jct. With CO RD 9 · Structure no. LR42-0.0-9

Built
1963
62 years old
Condition
Fair
inspected June 2023
Type
Tee Beam
Prestressed Concrete
Length
32 ft
1 main span
Daily traffic
153
2023 count
Owner
County
County Highway Agency

About this bridge

County Road 42 over Fossil Creek Res. Inlet is a prestressed concrete tee beam carrying County Road 42 over Fossil Creek Res. Inlet in Larimer County, Colorado. It was built in 1963, so it is 62 years old, older 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 5 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 153 vehicles a day, roughly 2% of them trucks, projected to reach 192 by 2042. The structure is 32 ft (9.8 m) long and 24 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesCounty Road 42
CrossesFossil Creek Res. Inlet
LocationJct. With CO RD 9
RouteCounty Highway 0
CountyLarimer County
StateColorado
Coordinates40.552, -105.02
Functional classUrban 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating49.6 US tons
Inventory rating29.9 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length32 ft (9.8 m)
Longest span27 ft (8.1 m)
Deck width24 ft (7.3 m)
Roadway width22 ft (6.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic153 (2023)
Projected traffic192 by 2042
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$151,000 (2019 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was County Road 42 over Fossil Creek Res. Inlet built?

It was built in 1963, making it 62 years old in 2025.

What condition is County Road 42 over Fossil Creek Res. Inlet 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 2023.

How much traffic does County Road 42 over Fossil Creek Res. Inlet carry?

About 153 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is County Road 42 over Fossil Creek Res. Inlet?

The structure is 32 ft (9.8 m) long with a longest span of 27 ft (8.1 m) and a deck 24 ft wide.

Who owns County Road 42 over Fossil Creek Res. Inlet?

It is owned by the County Highway Agency.