US Bridges

County Road 346 over Mamm Creek

FairPosted for load

Garfield County, Colorado · 300 Ft. South of I-70 · Structure no. GAR346-03.10-A

Built
1999
26 years old
Condition
Fair
inspected September 2023
Type
Slab
Wood or Timber
Length
30 ft
1 main span
Daily traffic
1,308
2023 count
Owner
County
County Highway Agency

About this bridge

County Road 346 over Mamm Creek is a wood or timber slab carrying County Road 346 over Mamm Creek in Garfield County, Colorado. It was built in 1999, so it is 26 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. Its operating status is: posted for load restriction.

It carries about 1,308 vehicles a day, roughly 31% of them trucks, projected to reach 1,661 by 2042. The structure is 30 ft (9.1 m) long and 30 ft wide. If it were closed, the detour would be 13 mi (21 km).

Location

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CarriesCounty Road 346
CrossesMamm Creek
Location300 Ft. South of I-70
RouteCounty Highway 0
CountyGarfield County
StateColorado
Coordinates39.53061, -107.71364
Functional classRural Minor Collector

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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44 US tons
Inventory rating28.7 US tons

Structure

Structure typeSlab
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length30 ft (9.1 m)
Longest span28 ft (8.5 m)
Deck width30 ft (9.2 m)
Roadway width28 ft (8.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,308 (2023)
Projected traffic1,661 by 2042
Trucks31%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed13 mi (21 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 346 over Mamm Creek built?

It was built in 1999, making it 26 years old in 2025.

What condition is County Road 346 over Mamm 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 September 2023.

How much traffic does County Road 346 over Mamm Creek carry?

About 1,308 vehicles per day (2023 count), of which roughly 31% are trucks.

How long is County Road 346 over Mamm Creek?

The structure is 30 ft (9.1 m) long with a longest span of 28 ft (8.5 m) and a deck 30 ft wide.

Who owns County Road 346 over Mamm Creek?

It is owned by the County Highway Agency.