Bridge conditions in Marathon County, Wisconsin
531 inventoried bridges · 40 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
40 of the 531 bridges the federal inventory lists in Marathon County are rated poor; the rest split 203 good and 288 fair.
- 40 of the 531 bridges in Marathon County, Wisconsin, are rated in poor condition (7.5%) in the 2025 National Bridge Inventory, as of .
- 203 bridges (38.2%) are rated good and 288 (54.2%) fair.
- The median Marathon County bridge was built in 1987.
- The busiest poor-rated bridge is Lrd Stewart Ave over Wisconsin River 31 (built 1915), carrying about 28,144 vehicles a day.
Good 38.2% · Fair 54.2% · Poor 7.5% of 531 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.
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Ih Ush 51-ih 39 NB over Ush Bus 51 & R.R. | 2012 | 39,600 | Fair |
| Ih 39 Sb/ush 51 over Ush Bus 51 | 2013 | 39,600 | Good |
| Ush 51NB over Lrd Stewart Ave | 2009 | 38,600 | Good |
| Ush 51 SB over Lrd Hwy 52 Parkway | 2007 | 38,600 | Good |
| Ih Ush 51-ih 39 SB over Wisconsin River 26 | 1968 | 37,700 | Good |
| Ush 51 NB over Lrd Sherman St | 2007 | 34,100 | Good |
| Ush 51SB over Lrd Sherman Ave | 2007 | 34,100 | Good |
| Ush 51 NB over Wis Central Ltd RR | 2007 | 34,100 | Good |
| Ush 51 SB over Wisconsin Central RR | 2007 | 34,100 | Good |
| Ush B51-grand Ave over Wisconsin Central Ltd | 1964 | 31,844 | 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 Marathon County → - all 531, busiest first, each with its own condition record.
All of Wisconsin: Wisconsin 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.