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Bridge conditions in Grundy County, Iowa

288 inventoried bridges · 77 rated poor · 2025 National Bridge Inventory

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

Grundy County has 77 bridges rated poor out of 288 inventoried, a 26.7% share that puts it well above the national rate of about 7%.

77 of the 288 bridges in Grundy County, Iowa, are rated in poor condition (26.7%) in the 2025 National Bridge Inventory, as of August 20, 2026.
120 bridges (41.7%) are rated good and 91 (31.6%) fair.
The median Grundy County bridge was built in 1981.
The busiest poor-rated bridge is Ia 14 over Black Hawk Creek (built 1931), carrying about 3,230 vehicles a day.

Good 41.7% · Fair 31.6% · Poor 26.7% of 288 bridges

Bridges rated poor

Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.

Bridge	Built	Vehicles/day	Condition
Ia 14 over Black Hawk Creek	1931	3,230	Poor
FM over Blackhawk Creek	1971	1,935	Poor
First St over Blackhawk Creek	1977	1,429	Poor
First St over Blackhawk Creek	1977	1,429	Poor
FM over Wolf Creek Branch	1975	1,394	Poor
FM over Creek	1966	707	Poor
FM over Black Hawk Creek	1979	687	Poor
FM over Branch Beaver Creek	1968	619	Poor
FM over Blackhawk Creek	1967	579	Poor
FM over Mosquito Creek	1977	501	Poor
FM over Beaver Creek	1973	501	Poor
FM over Dowd Creek	1972	491	Poor
FM over Branch Black Hawk Creek	1973	412	Poor
FM over Black Hawk Creek	1973	412	Poor
FM over Branch Beaver Creek	1966	393	Poor
FM over Wolf Creek Branch	1972	373	Poor
FM over Wolf Creek Branch	1972	285	Poor
FM over Blackhawk Creek Branch	1965	275	Poor
FM over Beaver Creek Branch	1932	265	Poor
Nickel Ave over Munns Creek	1955	216	Poor
FM over Dowd Creek Branch	1966	187	Poor
FM over Wolf Creek	1966	187	Poor
FM over Blackhawk Creek Branch	1956	177	Poor
FM over Blackhawk Creek Branch	1956	177	Poor
Local Road over Branch Beaver Creek	1975	100	Poor
Local Road over Middle Fork Beaver Creek	1952	99	Poor
FM over Dowd Creek	1964	98	Poor
FM over Beaver Creek Branch	1954	79	Poor
Local over Branch of Blackhawk Crk	1976	71	Poor
Local over Black Hawk Creek	1977	70	Poor
Local Road over Branch of Wolf Creek	1976	59	Poor
Local over Dowd Creek	1955	59	Poor
Local over Black Hawk Creek	1946	59	Poor
R Ave over Branch of Blackhawk Crk	1976	50	Poor
Local over Wolf Creek	1978	49	Poor
Local Road over Branch Blackhawk Crk	1976	49	Poor
Local over Branch Wolf Creek	1915	44	Poor
Local Road over Branch of Wolf Creek	1977	44	Poor
Local Road over Branch of Wolf Creek	1977	44	Poor
Local Road over Branch Black Hawk Creek	1973	44	Poor
Local Road over South Fork Beaver Creek	1948	44	Poor
Local over Br Beaver Creek	1978	44	Poor
Local over Branch of Beaver Creek	1953	40	Poor
Local Rd over South Fork Beaver Creek	1977	39	Poor
Local Road over Middle Fork Beaver Creek	1948	39	Poor
Local Road over North Fork Beaver	1981	39	Poor
Local over Little Wolf Creek	1976	33	Poor
Local Road over Branch Black Hawk Creek	1971	33	Poor
Local over Mosquito Creek	1983	33	Poor
Local over Branch Blackhawk Creek	1955	33	Poor
Local Road over Creek	1981	33	Poor
Local over Branch Wolf Creek	1956	30	Poor
Local Road over Branch Black Hawk Creek	1977	30	Poor
Local Road over Creek	1974	29	Poor
Local Road over Munns Creek	1971	29	Poor
Local Road over Branch Black Hawk Creek	1971	29	Poor
Local Rd over Branch Blackhawk Creek	1957	29	Poor
Local over Branch Beaver Creek	1971	29	Poor
Local Road over Branch Black Hawk Creek	1971	26	Poor
Local Rd over Branch Black Hawk Creek	1963	26	Poor
Local Rd over Branch Blackhawk Creek	1971	26	Poor
Local Road over Black Hawk Creek	1979	20	Poor
Local over Munns Creek	1957	20	Poor
Local Road over Beaver Creek	1978	20	Poor
Local Road over Middle Fork of Beaver CR	1976	20	Poor
Local Road over Dowd Creek	1977	15	Poor
Local Road over Creek	1977	15	Poor
Local Road over Branch of Wolf Creek	1953	15	Poor
Local Rd over Branch Blackhawk Creek	1956	15	Poor
Local Road over N Fork of Beaver Creek	1947	15	Poor
Local over Br Beaver Creek	1979	15	Poor
Local Road over Branch of Wolf Creek	1976	11	Poor
Local Road over Wolf Creek	1970	11	Poor
Local over Small	1978	11	Poor
Local Rd over Black Hawk Creek	1971	11	Poor
Local Road over Beaver Creek	1948	11	Poor
Local over Branch Wolf Creek	1914	5	Poor

Busiest bridges in the county

Bridge	Built	Vehicles/day	Condition
US 20 over Stream	1999	14,500	Good
US 20 over Stream	1999	13,500	Good
US 20 over Stream	1999	8,800	Good
US 20 WB over Grundy Rd	2000	6,800	Good
US 20 EB over Grundy Rd	2000	6,800	Good
US 20 WB over Stream	2000	6,800	Good
US 20 EB over Stream	2000	6,750	Good
US 20 EB over SR T55	2000	6,500	Good
WB US 20 over SR T55	2000	6,500	Good
US 20 EB over Local Stream	1999	6,500	Good

Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.

Every bridge in Grundy County → - all 288, busiest first, each with its own condition record.

All of Iowa: Iowa bridge conditions by county · every download on the data page.

Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.