Irr US018 over Ck

Oglala Lakota County, South Dakota · rated Good in the 2025 National Bridge Inventory

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

Irr US018 over Ck in Oglala Lakota County, South Dakota, is rated in good condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the culvert, rated 8 (very good condition) on the 0-9 scale.
It was built in 2011, making it 14 years old at the 2025 inventory.
It carries about 3,274 vehicles a day (traffic count year 2024).
Its listed owner is the state highway agency.
It is one of 20 of the 35 inventoried bridges in Oglala Lakota County rated good (57.1%); 2 (5.7%) 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 48-month routine inspection cycle.
A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.

Component ratings

Component	Rating (2024)	Rating (2025)	FHWA scale meaning
Culvert	8	8	Very good condition


Structure	Concrete culvert
Length	about 32 ft
Location	3.9 N of Pine Ridge
NBI structure number	000000057216439
Condition class	Good
Traffic status (item 41)	Open, no restriction
Last inspection (item 90)	August 2023
Inspection interval (item 91)	48 months
Scour (item 113)	8: foundations stable, scour above the top of the footing

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

Bridge	Built	Vehicles/day	Condition
Irr Bia Rte 36 over White Clay Creek	2001	7,551	Good
Irr US018 over Wolf Ck	2006	5,154	Fair
Irr US018 over Ck	2016	3,597	Good
Irr US018 over Cheyenne Ck	2020	3,274	Good
Irr Bia Rte 27 over White River	1985	2,368	Fair
Irr US018 over White Clay Ck	2011	2,131	Fair