US Bridges

SH 371 Ml over Alamosa River

Fair

Conejos County, Colorado · 1 MI No of JCT SH 15 · Structure no. O-12-AD

Built
1954
71 years old
Condition
Fair
inspected March 2023
Type
Tee Beam
Concrete
Length
93 ft
3 main spans
Daily traffic
790
2018 count
Owner
State
State Highway Agency

About this bridge

SH 371 Ml over Alamosa River is a concrete tee beam carrying SH 371 Ml over Alamosa River in Conejos County, Colorado. It was built in 1954, so it is 71 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 790 vehicles a day, roughly 16% of them trucks, projected to reach 1,185 by 2038. The structure is 93 ft (28.3 m) long and 28 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

CarriesSH 371 Ml
CrossesAlamosa River
Location1 MI No of JCT SH 15
RouteState Highway 371A
Coordinates37.29732, -106.03798
Functional classRural Minor Arterial

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 inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
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 adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating56.2 US tons
Inventory rating33.6 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length93 ft (28.3 m)
Longest span29 ft (8.7 m)
Deck width28 ft (8.5 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic790 (2018)
Projected traffic1,185 by 2038
Trucks16%
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

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost$146,000
NavigationNo navigation control on waterway

Frequently asked questions

When was SH 371 Ml over Alamosa River built?

It was built in 1954, making it 71 years old in 2025.

What condition is SH 371 Ml over Alamosa 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 March 2023.

How much traffic does SH 371 Ml over Alamosa River carry?

About 790 vehicles per day (2018 count), of which roughly 16% are trucks.

How long is SH 371 Ml over Alamosa River?

The structure is 93 ft (28.3 m) long with a longest span of 29 ft (8.7 m) and a deck 28 ft wide.

Who owns SH 371 Ml over Alamosa River?

It is owned by the State Highway Agency.