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486TH Avenue over Spring Creek

Brookings County, South Dakota · rated Poor in the 2025 National Bridge Inventory

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

486TH Avenue over Spring Creek in Brookings County, South Dakota, is rated in poor condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the deck, rated 3 (serious condition) on the 0-9 scale.
It was built in 1950, making it 75 years old at the 2025 inventory.
It carries about 361 vehicles a day (traffic count year 2022).
Its listed owner is the county highway agency.
It is one of 53 of the 232 inventoried bridges in Brookings County rated poor (22.8%); 53 (22.8%) are rated poor.
A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.

Component ratings


Structure	Steel stringer or multi-beam girder
Length	about 61 ft
Location	2.5S Elkton
NBI structure number	000000006320235
Condition class	Poor

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

Bridge	Built	Vehicles/day	Condition
I029 over Ck	1966	12,240	Fair
I029 over Ck	1966	12,240	Fair
I029 over Ck	1970	9,960	Fair
I029 over Ck	1970	9,960	Fair
I029 over Br Six Mile Ck	1970	9,960	Fair
US014 B over West Br Six Mile Ck	1967	9,030	Fair