Checked
Montana Bridge Conditions
Highway bridges longer than 20 feet in the 2025 National Bridge Inventory
Yearly inspection ratings. A poor rating does not mean a bridge is unsafe to use.
- Highway bridges
- 5,235
- Good condition
- 32.1%
- 1,682
- Poor condition
- 7.4%
- 388
- Weight-limited or closed
- 531
Bridges by county
| County | Bridges | Good | Poor | Weight-limited | Avg. year built |
|---|---|---|---|---|---|
| Beaverhead County | 227 | 23.3% | 10.6% (24) | 38 | 1979 |
| Big Horn County | 133 | 28.6% | 3.8% (5) | 6 | 1978 |
| Blaine County | 102 | 34.3% | 9.8% (10) | 24 | 1969 |
| Broadwater County | 37 | 27% | 10.8% (4) | 1 | 1990 |
| Carbon County | 81 | 38.3% | 4.9% (4) | 5 | 1986 |
| Carter County | 42 | 31% | 4.8% (2) | 4 | 1984 |
| Cascade County | 185 | 41.6% | 5.9% (11) | 19 | 1965 |
| Chouteau County | 43 | 58.1% | 4.7% (2) | 8 | 1982 |
| Custer County | 71 | 15.5% | 8.5% (6) | 3 | 1971 |
| Daniels County | 33 | 54.5% | 12.1% (4) | 4 | 1985 |
| Dawson County | 109 | 7.3% | 8.3% (9) | 14 | 1972 |
| Deer Lodge County | 67 | 38.8% | 4.5% (3) | 7 | 1974 |
| Fallon County | 38 | 44.7% | 5.3% (2) | 0 | 1997 |
| Fergus County | 158 | 32.9% | 5.7% (9) | 37 | 1979 |
| Flathead County | 204 | 33.8% | 4.4% (9) | 2 | 1983 |
| Gallatin County | 212 | 20.3% | 5.7% (12) | 28 | 1977 |
| Garfield County | 26 | 38.5% | 7.7% (2) | 0 | 1989 |
| Glacier County | 71 | 39.4% | 4.2% (3) | 3 | 1978 |
| Golden Valley County | 17 | 41.2% | 0% (0) | 2 | 1969 |
| Granite County | 73 | 38.4% | 12.3% (9) | 2 | 1974 |
| Hill County | 46 | 58.7% | 6.5% (3) | 3 | 1983 |
| Jefferson County | 136 | 19.1% | 5.1% (7) | 4 | 1977 |
| Judith Basin County | 45 | 57.8% | 15.6% (7) | 1 | 1979 |
| Lake County | 116 | 60.3% | 11.2% (13) | 14 | 1998 |
| Lewis and Clark County | 204 | 57.8% | 5.4% (11) | 23 | 1979 |
| Liberty County | 10 | 30% | 0% (0) | 1 | 1978 |
| Lincoln County | 191 | 36.6% | 15.2% (29) | 6 | 1977 |
| Madison County | 98 | 34.7% | 7.1% (7) | 9 | 1982 |
| McCone County | 43 | 11.6% | 9.3% (4) | 10 | 1967 |
| Meagher County | 53 | 18.9% | 13.2% (7) | 5 | 1980 |
| Mineral County | 153 | 24.2% | 11.1% (17) | 5 | 1972 |
| Missoula County | 206 | 32% | 7.3% (15) | 8 | 1976 |
| Musselshell County | 28 | 57.1% | 3.6% (1) | 3 | 1986 |
| Park County | 126 | 21.4% | 10.3% (13) | 17 | 1977 |
| Petroleum County | 26 | 30.8% | 15.4% (4) | 10 | 1967 |
| Phillips County | 101 | 12.9% | 21.8% (22) | 34 | 1973 |
| Pondera County | 96 | 51% | 4.2% (4) | 25 | 1975 |
| Powder River County | 23 | 52.2% | 0% (0) | 3 | 1988 |
| Powell County | 113 | 31.9% | 6.2% (7) | 5 | 1981 |
| Prairie County | 46 | 8.7% | 10.9% (5) | 4 | 1962 |
| Ravalli County | 150 | 40.7% | 8% (12) | 5 | 1983 |
| Richland County | 97 | 27.8% | 4.1% (4) | 6 | 1989 |
| Roosevelt County | 57 | 24.6% | 12.3% (7) | 4 | 1984 |
| Rosebud County | 112 | 16.1% | 6.3% (7) | 12 | 1973 |
| Sanders County | 120 | 37.5% | 8.3% (10) | 3 | 1979 |
| Sheridan County | 66 | 16.7% | 4.5% (3) | 5 | 1979 |
| Silver Bow County | 70 | 15.7% | 2.9% (2) | 4 | 1973 |
| Stillwater County | 92 | 30.4% | 1.1% (1) | 1 | 1977 |
| Sweet Grass County | 94 | 31.9% | 6.4% (6) | 5 | 1978 |
| Teton County | 82 | 41.5% | 3.7% (3) | 15 | 1975 |
| Toole County | 35 | 40% | 0% (0) | 0 | 1973 |
| Treasure County | 26 | 30.8% | 15.4% (4) | 6 | 1966 |
| Valley County | 103 | 15.5% | 10.7% (11) | 30 | 1980 |
| Wheatland County | 27 | 33.3% | 14.8% (4) | 1 | 1968 |
| Wibaux County | 25 | 12% | 4% (1) | 2 | 1975 |
| Yellowstone County | 290 | 33.4% | 2.4% (7) | 4 | 1981 |
Frequently asked questions
- How many bridges in Montana are in poor condition?
- In the 2025 National Bridge Inventory, 388 of 5,235 highway bridges in Montana were rated poor (7.4% of rated bridges).
- Which Montana counties have the most bridges in poor condition?
- Among counties with at least 30 bridges, the highest shares rated poor are Phillips County (21.8%), Judith Basin County (15.6%), Lincoln County (15.2%), Meagher County (13.2%), Granite County (12.3%).
Source: Federal Highway Administration, National Bridge Inventory · 2025 data