Montana bridges
Montana reports 5,235 bridges and culverts across 56 counties. 388 (7.4%) are rated in poor condition, and 531 are posted with load limits or closed. The oldest structure still in the inventory dates from 1881.
Find a bridge in Montana
Type at least two characters, or pick a condition or type, to search every bridge in the state.
Counties
Circle size reflects the number of bridges- Beaverhead County 227
- Big Horn County 133
- Blaine County 102
- Broadwater County 37
- Carbon County 81
- Carter County 42
- Cascade County 185
- Chouteau County 43
- Custer County 71
- Daniels County 33
- Dawson County 109
- Deer Lodge County 67
- Fallon County 38
- Fergus County 158
- Flathead County 204
- Gallatin County 212
- Garfield County 26
- Glacier County 71
- Golden Valley County 17
- Granite County 73
- Hill County 46
- Jefferson County 136
- Judith Basin County 45
- Lake County 116
- Lewis and Clark County 204
- Liberty County 10
- Lincoln County 191
- Madison County 98
- McCone County 43
- Meagher County 53
- Mineral County 153
- Missoula County 206
- Musselshell County 28
- Park County 126
- Petroleum County 26
- Phillips County 101
- Pondera County 96
- Powder River County 23
- Powell County 113
- Prairie County 46
- Ravalli County 150
- Richland County 97
- Roosevelt County 57
- Rosebud County 112
- Sanders County 120
- Sheridan County 66
- Silver Bow County 70
- Stillwater County 92
- Sweet Grass County 94
- Teton County 82
- Toole County 35
- Treasure County 26
- Valley County 103
- Wheatland County 27
- Wibaux County 25
- Yellowstone County 290
Condition
Good32%(1,682)
Fair60%(3,165)
Poor7%(388)
Counties with the highest share of poor bridges
- Phillips County21.8% of 101
- Judith Basin County15.6% of 45
- Petroleum County15.4% of 26
- Treasure County15.4% of 26
- Lincoln County15.2% of 191
Structure types
| Structure type | Bridges | Share |
|---|---|---|
| Stringer/Multi-beam or Girder | 3,394 | 64.8% |
| Tee Beam | 742 | 14.2% |
| Slab | 367 | 7.0% |
| Culvert | 363 | 6.9% |
| Channel Beam | 128 | 2.4% |
| Truss - Thru | 108 | 2.1% |
| Girder and Floorbeam System | 79 | 1.5% |
| Arch - Deck | 13 | 0.2% |
| Box Beam or Girders - Multiple | 13 | 0.2% |
| Truss - Deck | 7 | 0.1% |
| Frame | 6 | 0.1% |
| Other | 6 | 0.1% |
| Box Beam or Girders - Single or Spread | 3 | 0.1% |
| Mixed Types | 2 | 0.0% |
| Arch - Thru | 1 | 0.0% |
| Suspension | 1 | 0.0% |
| Segmental Box Girder | 1 | 0.0% |
| Orthotropic | 1 | 0.0% |
When Montana's bridges were built
Busiest
- N Reserve ST over Clark Fork R Flood PlainFairMissoula County · 35,914 vehicles/day
- N Reserve ST over Clark Fork RiverFairMissoula County · 35,914 vehicles/day
- Reserve ST over W Broadway St-RrFairMissoula County · 29,572 vehicles/day
- I90 over Mt Power RR SpurGoodYellowstone County · 29,488 vehicles/day
- Brooks St-Us 12 over Bitterroot RiverFairMissoula County · 28,185 vehicles/day
Longest
- Koocanusa Bridge over Koocanusa ReservoirFairLincoln County · 2,437 ft
- US 87-MT 3-MT 200 over Missouri RIVER-U5205-RRFairCascade County · 2,121 ft
- US 89-MT 3-MT 200 over Missouri RIVER-U5205-RRFairCascade County · 2,092 ft
- I 94 over Yellowstone RiverFairDawson County · 2,014 ft
- I 94 over Yellowstone RiverFairDawson County · 1,974 ft
Oldest
- S Howie ST over Reeders Alley 001FairLewis and Clark County · Built 1881
- Old Town RD over Jefferson River 063PoorGallatin County · Built 1894
- Augusta RD over Dearborn River 011FairLewis and Clark County · Built 1896
- Old Town RD over Jefferson River 004PoorGallatin County · Built 1897
- Williams Br RD over Jefferson River 046FairGallatin County · Built 1898
Newest
- S 56th Street West over Bbwa CanalGoodYellowstone County · Built 2024
- HWY 282 over Prickly Pear CreekGoodJefferson County · Built 2024
- Churchill RD over Stockpass DarinageGoodGallatin County · Built 2024
- Churchill RD S 288 over Camp CreekGoodGallatin County · Built 2024
- US 2 over Chapman CouleeGoodValley County · Built 2024
Who owns Montana's bridges
| State | 2,424 | 46.3% |
| County | 1,963 | 37.5% |
| Federal | 803 | 15.3% |
| City | 40 | 0.8% |
| Tribal | 2 | 0.0% |
| Railroad | 1 | 0.0% |
| Local | 1 | 0.0% |
| Private | 1 | 0.0% |
More Montana facts
Total bridge length119 miles
Total deck area22,567,399 sq ft
Culverts counted as bridges363 (7%)
On the National Highway System1,360
Posted with load limits500
Closed to traffic31
Listed or eligible for the National Register46
Average daily traffic per bridge1,642 vehicles
Newest structure2024