Bridge conditions in Mason County, Michigan
66 inventoried bridges · 4 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
The federal inventory lists 66 bridges in Mason County: 21 rated good, 41 fair, and 4 poor.
- 4 of the 66 bridges in Mason County, Michigan, are rated in poor condition (6.1%) in the 2025 National Bridge Inventory, as of .
- 21 bridges (31.8%) are rated good and 41 (62.1%) fair.
- The median Mason County bridge was built in 1986.
- The busiest poor-rated bridge is Cleveland St over N Br Lincoln River (built 1960), carrying about 425 vehicles a day.
Good 31.8% · Fair 62.1% · Poor 6.1% of 66 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 |
|---|---|---|---|
| Cleveland St over N Br Lincoln River | 1960 | 425 | Poor |
| Tyndall Road over Big Sable River | 1900 | 200 | Poor |
| Wilson Road over S Br Pere Marquette Rivr | 1900 | 100 | Poor |
| Younkers Road over Big Sauble River | 1960 | 49 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Old US-31 over CSX RR | 1935 | 11,200 | Good |
| Old US-31 over Durham Creek | 1925 | 8,600 | Fair |
| Old US-31 over Pere Marquette River | 1925 | 7,076 | Fair |
| Old US-31 over Pere Marquette River | 1924 | 6,828 | Fair |
| US-31 over S Br Lincoln River | 1992 | 6,578 | Fair |
| US-31 over N Br Lincoln River | 1992 | 6,578 | Fair |
| US-31 over Big Sable River | 1959 | 6,578 | Fair |
| Washington Ave over Pere Marquette Lk Bayou | 2013 | 6,340 | Good |
| Jebavy Road over Lincoln River | 1988 | 6,000 | Fair |
| US-10 over Weldon Creek | 1938 | 5,307 | Fair |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of Michigan: Michigan 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.