185 Street over Medicine Knoll Ck

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

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

• 185 Street over Medicine Knoll 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 superstructure, rated 5 (fair condition) on the 0-9 scale.
• It was built in 1930 and reconstructed in 1958, making it 95 years old at the 2025 inventory.
• It carries about 150 vehicles a day (traffic count year 2022).
• Its listed owner is the county 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 condition class and component ratings are unchanged from the 2024 inventory.
• Its most recent inspection on record is dated August 2023, on a 24-month routine inspection cycle.
• 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 → (44.70779, -99.77273)

Component ratings

Bridge details

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

Busiest bridges in Sully County

All bridges nearby: Sully County, SD bridge conditions · every bridge in Sully County · South Dakota bridges.

Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.