Structure 65072059 · Walworth County, SD

Sd1804 over Blue Blanket Ck

Carries Sd1804 over Blue Blanket Ck, 2.5 S Jct US 12.

Overall conditionFair

Set by its lowest-rated component: Substructure at 5 of 9.

How ratings work
Deck6/9 · Satisfactory
Superstructure6/9 · Satisfactory
Substructuresets the rating5/9 · Fair
Channelnot part of overall7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT129 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9Superstructure 6/9Substructure 5/9 · sets the rating

129 ft end to end, longest span 26 ft. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a slab bridge.

Built196165 years old
Length128.6 ft39.2 m
Daily traffic272counted 2024
Last inspectedDecember 2024every 24 months

Location

StateSouth Dakota
CountyWalworth
Location2.5 S Jct US 12
CarriesSd1804
CrossesBlue Blanket Ck
Coordinates45.50957, -100.32199

Physical Characteristics

MaterialConcrete Continuous
DesignSlab
Total Length128.6 ft (39.2 m)
Max Span25.9 ft (7.9 m)
Deck Width28.2 ft (8.6 m)
Deck Area337.1 sq m
Main Spans5
Year Built1961

Traffic

Avg Daily Traffic272 (2024)
Truck Traffic6%
Lanes On Bridge2

Inspection & Ownership

Last InspectionDecember 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical7 — Countermeasures installed
Structure Number000000065072059

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

Nearby Bridges