Scour Critical Bridges in Montana
166 bridges in Montana at risk from water erosion around foundations.
Scour Critical Bridges
Scour is the erosion of soil and rock around a bridge's foundation caused by moving water. When foundations are exposed or undermined, a bridge can collapse even if its deck and superstructure are in good condition. Scour is the leading cause of bridge failures in the US. These 166 bridges in Montana have been identified as vulnerable to scour damage.
| Bridge | State | Scour Status | Condition | Year Built | ADT |
|---|---|---|---|---|---|
| BIG LAKE CREEK 081 | Montana | Scour Critical — Unaddressed | Poor | 1958 | 100 |
| BIG HOLE RIVER 123 | Montana | Scour Critical — Unaddressed | Poor | 1915 | 100 |
| BOX ELDER CREEK 008 | Montana | Scour Critical — Unaddressed | Poor | 1930 | 100 |
| RYE CREEK 064 | Montana | Scour Critical — Unaddressed | Fair | 1975 | 100 |
| LITTLE BITTERROOT RV 092 | Montana | Scour Critical — Unaddressed | Fair | 2002 | 100 |
| SWAMP GUL | Montana | Scour Critical — Unaddressed | Poor | 1987 | 50 |
| CEDAR CR | Montana | Scour Critical — Unaddressed | Poor | 1959 | 50 |
| Sun River | Montana | Scour Critical — Unaddressed | Poor | 1916 | 40 |
| WHITEWATER CREEK | Montana | Scour Critical — Unaddressed | Poor | 1976 | 39 |
| IRRIGATION DITCH 005 | Montana | Scour Critical — Unaddressed | Poor | 1979 | 17 |
| SPAR CR | Montana | Scour Critical — Unaddressed | Poor | 1955 | 10 |
| WISE RIVER | Montana | Scour Critical — Unaddressed | Poor | 1992 | 6 |
| NO DATA ENTERED | Montana | Scour Critical — Unaddressed | Fair | 1987 | 5 |
| MCDONALD CREEK | Montana | Scour Critical — Countermeasures Ineffective | Good | 2024 | 200 |
| BOULDER RIVER | Montana | Scour Critical — Countermeasures Ineffective | Fair | 1940 | 157 |
| TENMILE CREEK | Montana | Scour Critical — Countermeasures Ineffective | Good | 2023 | 107 |
| North Fork Sunday Creek | Montana | Scour Critical — Countermeasures Ineffective | Good | 2024 | 100 |
| DRAINAGE | Montana | Scour Critical — Countermeasures Ineffective | Poor | 1953 | 100 |
| DIRTY WOMAN CREEK | Montana | Scour Critical — Countermeasures Ineffective | Fair | 1970 | 100 |
| DRAINAGE | Montana | Scour Critical — Countermeasures Ineffective | Fair | 1980 | 100 |
| Dog Creek | Montana | Scour Critical — Countermeasures Ineffective | Good | 2024 | 100 |
| POORMAN CREEK | Montana | Scour Critical — Countermeasures Ineffective | Good | 2024 | 89 |
| S FK JUDITH RIVER | Montana | Scour Critical — Countermeasures Ineffective | Poor | 1958 | 65 |
| MOOSE CREEK | Montana | Scour Critical — Countermeasures Ineffective | Poor | 1956 | 50 |
| W FK COTTONWOOD CREEK | Montana | Scour Critical — Countermeasures Ineffective | Fair | 1969 | 50 |
| SPRING CREEK | Montana | Scour Critical — Countermeasures Ineffective | Good | 1996 | 50 |
| GALLATIN RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1965 | 9,726 |
| GALLATIN RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1965 | 9,726 |
| STILLWATER RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1975 | 7,156 |
| BITTERROOT RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1949 | 6,979 |
| YELLOWSTONE RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1962 | 6,397 |
| YELLOWSTONE RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1962 | 6,397 |
| PRICKLY PEAR CREEK | Montana | Scour Critical — Countermeasures Installed | Fair | 1941 | 6,170 |
| BITTERROOT RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1954 | 5,076 |
| YELLOWSTONE RIVER | Montana | Scour Critical — Countermeasures Installed | Poor | 1957 | 5,017 |
| HYALITE CREEK | Montana | Scour Critical — Countermeasures Installed | Good | 2022 | 4,997 |
| YELLOWSTONE RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1930 | 4,964 |
| YELLOWSTONE RIVER 170 | Montana | Scour Critical — Countermeasures Installed | Poor | 1949 | 4,005 |
| BITTERROOT RIVER 010 | Montana | Scour Critical — Countermeasures Installed | Fair | 1935 | 3,627 |
| COUGAR CREEK | Montana | Scour Critical — Countermeasures Installed | Fair | 1964 | 3,139 |
| BEAVERHEAD RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1949 | 2,865 |
| BITTERROOT RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1974 | 2,814 |
| YELLOWSTONE RIVER | Montana | Scour Critical — Countermeasures Installed | Poor | 1994 | 2,438 |
| DIVIDE CREEK | Montana | Scour Critical — Countermeasures Installed | Fair | 1934 | 2,300 |
| GARDNER RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1958 | 2,294 |
| GALLATIN RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1951 | 1,889 |
| SKALKAHO CREEK 053 | Montana | Scour Critical — Countermeasures Installed | Poor | 1941 | 1,713 |
| BEAVER CREEK | Montana | Scour Critical — Countermeasures Installed | Fair | 1949 | 1,671 |
| JEFFERSON RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1949 | 1,515 |
| YELLOWSTONE RIVER 004 | Montana | Scour Critical — Countermeasures Installed | Fair | 1949 | 1,471 |
Scour Critical Rating Codes
| Code 2 — Unaddressed | Bridge is scour critical with no countermeasures installed. The foundation is vulnerable and no protective action has been taken. |
| Code 3 — Countermeasures Installed | Protective measures (riprap, sheet piling, etc.) have been installed to reduce scour risk, but the bridge remains classified as scour critical. |
| Code 6 — Countermeasures Ineffective | Protective measures were installed but have been assessed as ineffective. The bridge requires re-evaluation and additional action. |
About Scour Critical Bridges
Scour critical bridges have been identified through underwater inspection or analysis as having foundations that are unstable or could become unstable during flood conditions. FHWA requires action plans for all scour critical bridges. Famous scour failures include the 1987 Schoharie Creek Bridge collapse in New York.