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Irr SD020 over Irish Ck

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

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

Irr SD020 over Irish Ck in Ziebach 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 superstructure, rated 7 (good condition) on the 0-9 scale.
It was built in 1975, making it 50 years old at the 2025 inventory.
It carries about 125 vehicles a day (traffic count year 2024).
Its listed owner is the state highway agency.
It is one of 7 of the 30 inventoried bridges in Ziebach County rated good (23.3%); 3 (10.0%) are rated poor.
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


Structure	Continuous prestressed concrete stringer or multi-beam girder
Length	about 157 ft
Location	7.5 E of Glad Valley
NBI structure number	000000069195060
Condition class	Good

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

Bridge	Built	Vehicles/day	Condition
Irr US212 over Ck	1954	1,291	Fair
Irr US212 over Bear Ck	1954	1,130	Fair
Irr US212 over Bear Ck	1955	1,083	Fair
Irr Bia Rte 6 over Ash Creek	1968	814	Good
Irr SD063 over Rudy Ck Tributary	1994	590	Fair
Irr SD063 over Rudey Ck	1993	590	Fair