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County Road 59 over South Platte River

Washington County, Colorado · rated Fair in the 2025 National Bridge Inventory

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

County Road 59 over South Platte River in Washington County, Colorado, is rated in fair condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the substructure, rated 5 (fair condition) on the 0-9 scale.
It was built in 1986, making it 39 years old at the 2025 inventory.
It carries about 53 vehicles a day (traffic count year 2023).
Its listed owner is the county highway agency.
It is one of 59 of the 76 inventoried bridges in Washington County rated fair (77.6%); 3 (3.9%) are rated poor.
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.

Component ratings


Structure	Steel stringer or multi-beam girder
Length	about 262 ft
Location	0.5 Mi. E. of Co. Rd. Q
NBI structure number	WTN59-Q.50-A
Condition class	Fair

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

Bridge	Built	Vehicles/day	Condition
I 76 Ml Wbnd over County Road Q	1964	5,500	Fair
I 76 Ml Ebnd over County Road Q	1964	5,500	Fair
US 34 Ml over Camp Creek	2000	3,300	Good
US 34 Ml over Draw	2006	3,100	Good
US 34 Ml over Surveyor Creek	1935	2,900	Fair
US 6 Ml over Prewitt Res Intake Canal	1941	1,100	Fair