US Bridges

Mn 9 over Buffalo River

Fair

Clay County, Minnesota · 0.1 MI N of JCT TH 10 · Structure no. 14005

Built
1979
46 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
58 ft
2 main spans
Daily traffic
2,085
2022 count
Owner
State
State Highway Agency

About this bridge

Mn 9 over Buffalo River is a steel stringer/multi-beam or girder carrying Mn 9 over Buffalo River in Clay County, Minnesota. It was built in 1979, so it is 46 years old, older than the Minnesota average of 38.5 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 2,085 vehicles a day, roughly 24% of them trucks, projected to reach 1,900 by 2042. The structure is 58 ft (17.7 m) long and 50 ft wide. If it were closed, the detour would be 21.1 mi (34 km).

Location

Open in Google Maps
CarriesMn 9
CrossesBuffalo River
Location0.1 MI N of JCT TH 10
RouteState Highway 9
CountyClay County
StateMinnesota
Coordinates46.87955, -96.50534
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2023
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 geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating109.8 US tons
Inventory rating72.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length58 ft (17.7 m)
Longest span29 ft (8.7 m)
Deck width50 ft (15.3 m)
Roadway width47 ft (14.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,085 (2022)
Projected traffic1,900 by 2042
Trucks24%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed21.1 mi (34 km)
TollOn a free road
National Highway SystemNo

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 Mn 9 over Buffalo River built?

It was built in 1979, making it 46 years old in 2025.

What condition is Mn 9 over Buffalo 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 September 2023.

How much traffic does Mn 9 over Buffalo River carry?

About 2,085 vehicles per day (2022 count), of which roughly 24% are trucks.

How long is Mn 9 over Buffalo River?

The structure is 58 ft (17.7 m) long with a longest span of 29 ft (8.7 m) and a deck 50 ft wide.

Who owns Mn 9 over Buffalo River?

It is owned by the State Highway Agency.