US Bridges

Cth N over Black River

Fair

Clark County, Wisconsin · 0.6M E JCT Cth O · Structure no. B10098100000000

Built
1948
77 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
279 ft
4 main spans
Daily traffic
394
2022 count
Owner
County
County Highway Agency

About this bridge

Cth N over Black River is a steel continuous stringer/multi-beam or girder carrying Cth N over Black River in Clark County, Wisconsin. It was built in 1948, so it is 77 years old, older than the Wisconsin average of 40.3 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 394 vehicles a day, projected to reach 433 by 2042. The structure is 279 ft (85 m) long and 25 ft wide. If it were closed, the detour would be 10.6 mi (17 km).

Location

Open in Google Maps
CarriesCth N
CrossesBlack River
Location0.6M E JCT Cth O
RouteCounty Highway 0N
CountyClark County
StateWisconsin
Coordinates44.91514, -90.64701
Functional classRural Minor 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 protection8 Very GoodNo problems noted.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
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 adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating37.8 US tons
Inventory rating23.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length279 ft (85 m)
Longest span76 ft (23.2 m)
Deck width25 ft (7.5 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic394 (2022)
Projected traffic433 by 2042
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed10.6 mi (17 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 Cth N over Black River built?

It was built in 1948, making it 77 years old in 2025.

What condition is Cth N over Black 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 2023.

How much traffic does Cth N over Black River carry?

About 394 vehicles per day (2022 count).

How long is Cth N over Black River?

The structure is 279 ft (85 m) long with a longest span of 76 ft (23.2 m) and a deck 25 ft wide.

Who owns Cth N over Black River?

It is owned by the County Highway Agency.