US Bridges

Csah 8 over Knife River

Fair

Kanabec County, Minnesota · 0.4 MI S of JCT CR 88 · Structure no. 33506

Built
1967
58 years old
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
112 ft
3 main spans
Daily traffic
275
2018 count
Owner
County
County Highway Agency

About this bridge

Csah 8 over Knife River is a steel continuous stringer/multi-beam or girder carrying Csah 8 over Knife River in Kanabec County, Minnesota. It was built in 1967, so it is 58 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 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 275 vehicles a day, projected to reach 290 by 2038. The structure is 112 ft (34 m) long and 33 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesCsah 8
CrossesKnife River
Location0.4 MI S of JCT CR 88
RouteCounty Highway 8
CountyKanabec County
StateMinnesota
Coordinates45.97479, -93.329
Functional classRural Major Collector

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating48.9 US tons
Inventory rating29.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length112 ft (34 m)
Longest span41 ft (12.6 m)
Deck width33 ft (10 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic275 (2018)
Projected traffic290 by 2038
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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 Csah 8 over Knife River built?

It was built in 1967, making it 58 years old in 2025.

What condition is Csah 8 over Knife 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 November 2023.

How much traffic does Csah 8 over Knife River carry?

About 275 vehicles per day (2018 count).

How long is Csah 8 over Knife River?

The structure is 112 ft (34 m) long with a longest span of 41 ft (12.6 m) and a deck 33 ft wide.

Who owns Csah 8 over Knife River?

It is owned by the County Highway Agency.