US Bridges

CR 56 over Rock Creek

Fair

Chisago County, Minnesota · 0.2 MI S of JCT Csah 3 · Structure no. 13509

Built
1976
49 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
80 ft
1 main span
Daily traffic
129
2022 count
Owner
County
County Highway Agency

About this bridge

CR 56 over Rock Creek is a prestressed concrete stringer/multi-beam or girder carrying CR 56 over Rock Creek in Chisago County, Minnesota. It was built in 1976, so it is 49 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 129 vehicles a day, projected to reach 140 by 2042. The structure is 80 ft (24.3 m) long and 36 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesCR 56
CrossesRock Creek
Location0.2 MI S of JCT Csah 3
RouteCounty Highway 56
CountyChisago County
StateMinnesota
Coordinates45.71394, -92.87327
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
Deck8 Very GoodNo problems noted.
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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionSeptember 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 geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating52.9 US tons
Inventory rating31.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length80 ft (24.3 m)
Longest span77 ft (23.5 m)
Deck width36 ft (10.9 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic129 (2022)
Projected traffic140 by 2042
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 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 CR 56 over Rock Creek built?

It was built in 1976, making it 49 years old in 2025.

What condition is CR 56 over Rock Creek 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 CR 56 over Rock Creek carry?

About 129 vehicles per day (2022 count).

How long is CR 56 over Rock Creek?

The structure is 80 ft (24.3 m) long with a longest span of 77 ft (23.5 m) and a deck 36 ft wide.

Who owns CR 56 over Rock Creek?

It is owned by the County Highway Agency.