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Island Ranch Road over Chapman Slough

Harney County, Oregon · rated Fair in the 2025 National Bridge Inventory

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

Island Ranch Road over Chapman Slough in Harney County, Oregon, is rated in fair condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the substructure, rated 6 (satisfactory condition) on the 0-9 scale.
It was built in 2009, making it 16 years old at the 2025 inventory.
It carries about 90 vehicles a day (traffic count year 2020).
Its listed owner is the county highway agency.
It is one of 61 of the 128 inventoried bridges in Harney County rated fair (47.7%); 2 (1.6%) 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

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

Bridge	Built	Vehicles/day	Condition
US 20 (hwy 007) over Silvies River	1999	2,834	Good
US 20 (hwy 007) over Willow Creek	1993	2,792	Fair
US 20 (hwy 007) over Poison Creek(susans Br)	1966	2,332	Good
US 20 (hwy 007) over Foley Slough	1999	2,332	Good
US 20 (hwy 007) over Silver Creek	1956	2,325	Fair
US 20 (hwy 007) over Miller Creek	2004	2,325	Good