Structure 6665 · St. Louis County, MN

Csah 4 over Island Lake

Carries Csah 4 over Island Lake, 0.6 Mi S Of Jct Cr269.

Overall conditionFair

Set by its lowest-rated component: Substructure at 6 of 9.

How ratings work
Deck7/9 · Good
Superstructure7/9 · Good
Substructuresets the rating6/9 · Satisfactory
Channelnot part of overall8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT234 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 7/9Substructure 6/9 · sets the rating

234 ft end to end, longest span 90 ft: about 3 semi-trucks nose to tail. 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 multi-beam bridge.

Built194977 years old
Length234.3 ft71.4 m
Daily traffic2,907counted 2022
Last inspectedSeptember 2024every 24 months

Location

StateMinnesota
CountySt. Louis
Location0.6 Mi S Of Jct Cr269
CarriesCsah 4
CrossesIsland Lake
Coordinates47.02458, -92.14625

Physical Characteristics

MaterialSteel Continuous
DesignStringer/Multi-beam
Total Length234.3 ft (71.4 m)
Max Span89.9 ft (27.4 m)
Deck Width50.2 ft (15.3 m)
Deck Area1092.4 sq m
Main Spans3
Year Built1949

Traffic

Avg Daily Traffic2,907 (2022)
Truck Traffic8%
Lanes On Bridge2

Inspection & Ownership

Last InspectionSeptember 2024
Inspection FrequencyEvery 24 months
OwnerCounty Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number6665

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.