US Bridges

Gentian Trail over Blackbird CR

Good

Putnam County, Missouri · S 34 T 65 N R 17 W · Structure no. 20791

Built
1999
26 years old
Condition
Good
inspected February 2023
Type
Tee Beam
Prestressed Concrete
Length
111 ft
3 main spans
Daily traffic
40
2024 count
Owner
County
County Highway Agency

About this bridge

Gentian Trail over Blackbird CR is a prestressed concrete tee beam carrying Gentian Trail over Blackbird CR in Putnam County, Missouri. It was built in 1999, so it is 26 years old, younger than the Missouri average of 45.1 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 40 vehicles a day, roughly 10% of them trucks, projected to reach 44 by 2044. The structure is 111 ft (33.8 m) long and 25 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

CarriesGentian Trail
CrossesBlackbird CR
LocationS 34 T 65 N R 17 W
RouteCounty Highway 275
Coordinates40.39587, -92.78581
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionFebruary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating93.3 US tons
Inventory rating55.6 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length111 ft (33.8 m)
Longest span39 ft (11.9 m)
Deck width25 ft (7.5 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic40 (2024)
Projected traffic44 by 2044
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 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 Gentian Trail over Blackbird CR built?

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

What condition is Gentian Trail over Blackbird CR in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in February 2023.

How much traffic does Gentian Trail over Blackbird CR carry?

About 40 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is Gentian Trail over Blackbird CR?

The structure is 111 ft (33.8 m) long with a longest span of 39 ft (11.9 m) and a deck 25 ft wide.

Who owns Gentian Trail over Blackbird CR?

It is owned by the County Highway Agency.