SD1804 over Okobojo Ck

Sully County, South Dakota · rated Fair in the 2025 National Bridge Inventory

United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled August 20, 2026

• SD1804 over Okobojo Ck in Sully County, South Dakota, is rated in fair condition in the 2025 National Bridge Inventory (as of August 20, 2026).
• Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
• It was built in 1972, making it 53 years old at the 2025 inventory.
• It carries about 632 vehicles a day (traffic count year 2024).
• Its listed owner is the state highway agency.
• It is one of 11 of the 31 inventoried bridges in Sully County rated fair (35.5%); 6 (19.4%) are rated poor.
• Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
• Its class is unchanged from 2024 (fair), but component ratings moved: deck 8 to 6.
• Its most recent inspection on record is dated July 2024, on a 12-month routine inspection cycle.
• It is coded scour critical (NBI item 113 = 3): scour critical: foundations unstable for the assessed or calculated scour.
• A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.

View this bridge on a map → (44.62428, -100.44621)

Component ratings

Bridge details

Source: FHWA National Bridge Inventory, 2025 data as reported by the South Dakota department of transportation.

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