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Bridge conditions in Harrison County, Iowa

222 inventoried bridges · 41 rated poor · 2025 National Bridge Inventory

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

About one in 5 bridges in Harrison County is rated in poor condition: 41 of 222 on the federal inventory, one of the higher shares in Iowa.

41 of the 222 bridges in Harrison County, Iowa, are rated in poor condition (18.5%) in the 2025 National Bridge Inventory, as of August 20, 2026.
61 bridges (27.5%) are rated good and 120 (54.1%) fair.
The median Harrison County bridge was built in 1968.
The busiest poor-rated bridge is FM Easton Trail over Allen Creek (built 1969), carrying about 335 vehicles a day.

Good 27.5% · Fair 54.1% · Poor 18.5% of 222 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
FM Easton Trail over Allen Creek	1969	335	Poor
FM Laredo Ave over Allen Creek	1942	139	Poor
L23 Laredo Ave over Steer Creek	1942	139	Poor
8TH Street over Boyer River	1900	123	Poor
FM - 335TH St over Mosquito Creek	1920	120	Poor
FM Tabor Ave over Small Stream	1956	110	Poor
Loc Canal St over Willow River	1916	100	Poor
Medford Ave over Willow River	1900	89	Poor
Loc 128 Trail over Boyer River	1940	89	Poor
198TH St over Small Creek	1950	79	Poor
FM & 155TH St over Mud Creek	1940	79	Poor
FM - 335TH St over Small Creek	1952	71	Poor
Vienna Ave over Pigeon Creek	1967	60	Poor
Jasper Trail over Small Creek	1900	50	Poor
Local Taylor Av over Small Creek	1955	45	Poor
Neely Trail over Willow Creek	1940	45	Poor
Taylor Ave over Pigeon Creek	1920	40	Poor
Local 120TH St over Little Sioux River	1971	40	Poor
288TH St over Mosquito Creek	1940	34	Poor
Toledo Ave over Pigeon Creek	1951	34	Poor
242ND Trail over Drainage Ditch	2013	34	Poor
Parker Trail over Small Creek	1916	29	Poor
Mobile Ave over Hoffman Creek	1940	29	Poor
Loc 215TH St over Pigeon Creek	1955	26	Poor
280TH St over Mosquito Creek	1940	20	Poor
305TH St over Keg Creek	1957	20	Poor
315TH St over Mosquito Creek	1930	20	Poor
Loc 335TH St over Allen Creek	1959	20	Poor
FM & Nash Trail over Allen Creek	1976	20	Poor
240TH Street over Pigeon Creek	1967	15	Poor
180TH St over Willow Creek	1975	15	Poor
325TH St over Keg Creek	1900	11	Poor
325TH St over Pigeon Creek	1960	11	Poor
Reno Ave over Six Mile Creek	1930	11	Poor
250TH St over Allen Creek	1965	11	Poor
Loc 210TH St over Little Pigeon	1930	11	Poor
155TH St over Willow River	1930	11	Poor
Mobile Ave over Allen Creek	1957	11	Poor
185TH Lane over Allen Creek	1986	5	Poor
Kendall Trail over Steer Creek	1969	5	Poor
125TH St over Small Stream	1960	5	Poor

Busiest bridges in the county

Bridge	Built	Vehicles/day	Condition
US 30 over Willow Creek	1972	10,300	Fair
US 30 over UPRR	1998	10,300	Good
NB I-29 over Boyer River	1958	10,050	Fair
SB I-29 over Boyer River	1958	10,050	Fair
SB I-29 over over UP RR	1967	7,750	Fair
NB I-29 over Allen Creek	1967	7,750	Fair
SB I-29 over Allen Creek	1967	7,750	Fair
NB I-29 over UP RR & K-45	1967	7,600	Fair
SB I-29 over UP RR & K-45	1967	7,600	Fair
NB I-29 over Old Soldier River Ditch	1967	7,600	Fair

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

Every bridge in Harrison County → - all 222, 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.