US Bridges

County Road 21 over Animas River

Fair

San Juan County, Colorado · 2.9 MI NE of Silverton · Structure no. SJN21-00.2A

Built
1989
36 years old
Condition
Fair
inspected June 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
62 ft
1 main span
Daily traffic
81
2022 count
Owner
County
County Highway Agency

About this bridge

County Road 21 over Animas River is a steel stringer/multi-beam or girder carrying County Road 21 over Animas River in San Juan County, Colorado. It was built in 1989, so it is 36 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 81 vehicles a day, projected to reach 84 by 2042. The structure is 62 ft (18.8 m) long and 23 ft wide. If it were closed, the detour would be 100 mi (161 km).

Location

Open in Google Maps
CarriesCounty Road 21
CrossesAnimas River
Location2.9 MI NE of Silverton
RouteCounty Highway 0
CountySan Juan County
StateColorado
Coordinates37.82719, -107.62633
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.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
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 alignment6: Equal to present minimum criteria
Operating rating72.4 US tons
Inventory rating43.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length62 ft (18.8 m)
Longest span58 ft (17.8 m)
Deck width23 ft (7.1 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic81 (2022)
Projected traffic84 by 2042
Trucks0%
Lanes on structure2
Traffic directionTwo-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 21 over Animas River built?

It was built in 1989, making it 36 years old in 2025.

What condition is County Road 21 over Animas 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 June 2024.

How much traffic does County Road 21 over Animas River carry?

About 81 vehicles per day (2022 count).

How long is County Road 21 over Animas River?

The structure is 62 ft (18.8 m) long with a longest span of 58 ft (17.8 m) and a deck 23 ft wide.

Who owns County Road 21 over Animas River?

It is owned by the County Highway Agency.