US Bridges

US 491 Ml over Cahone Creek

Fair

Dolores County, Colorado · 24.6 MI NW of JCT US 160 · Structure no. N-01-H

Built
1937
88 years old, rebuilt 1960
Condition
Fair
inspected February 2025
Type
Culvert
Concrete
Length
44 ft
3 main spans
Daily traffic
3,200
2020 count
Owner
State
State Highway Agency

About this bridge

US 491 Ml over Cahone Creek is a concrete culvert carrying US 491 Ml over Cahone Creek in Dolores County, Colorado. It was built in 1937 and reconstructed in 1960, so it is 88 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 3,200 vehicles a day, roughly 27% of them trucks, projected to reach 3,744 by 2040. The structure is 44 ft (13.4 m) long and 107 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

CarriesUS 491 Ml
CrossesCahone Creek
Location24.6 MI NW of JCT US 160
RouteU.S. Route 491B
Coordinates37.64893, -108.80829
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 protection7 GoodSome minor problems.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: 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 rating99 US tons
Inventory rating99 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans3
Design loadHS 20
Structure length44 ft (13.4 m)
Longest span14 ft (4.3 m)
Deck width107 ft (32.5 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,200 (2020)
Projected traffic3,744 by 2040
Trucks27%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 491 Ml over Cahone Creek built?

It was built in 1937, making it 88 years old in 2025. It was reconstructed in 1960.

What condition is US 491 Ml over Cahone 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 February 2025.

How much traffic does US 491 Ml over Cahone Creek carry?

About 3,200 vehicles per day (2020 count), of which roughly 27% are trucks.

How long is US 491 Ml over Cahone Creek?

The structure is 44 ft (13.4 m) long with a longest span of 14 ft (4.3 m) and a deck 107 ft wide.

Who owns US 491 Ml over Cahone Creek?

It is owned by the State Highway Agency.