Bridge conditions in Lewis and Clark County, Montana
204 inventoried bridges · 11 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
Lewis and Clark County tracks close to typical: 11 of its 204 inventoried bridges (5.4%) are rated poor, against a national rate of about 7%.
- 11 of the 204 bridges in Lewis and Clark County, Montana, are rated in poor condition (5.4%) in the 2025 National Bridge Inventory, as of .
- 118 bridges (57.8%) are rated good and 75 (36.8%) fair.
- The median Lewis and Clark County bridge was built in 1978.
- The busiest poor-rated bridge is Lincoln Rd over Int Lincoln-i 15 (built 1962), carrying about 7,492 vehicles a day.
Good 57.8% · Fair 36.8% · Poor 5.4% of 204 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 |
|---|---|---|---|
| Lincoln Rd over Int Lincoln-i 15 | 1962 | 7,492 | Poor |
| Frontage Road 295 over Ten Mile Creek 071 | 1962 | 1,929 | Poor |
| S Cruse Ave over Pedestrian Underpass | 1972 | 1,548 | Poor |
| S 200 over Stockpass | 1949 | 1,432 | Poor |
| Craig Frontage Rd over Missouri River 054 | 1933 | 484 | Poor |
| Lovers Lane over Elk Creek 041 | 1914 | 100 | Poor |
| Birdtail Rd over Flat Creek 036 | 1901 | 100 | Poor |
| Fdr #8983 over N Fk Sun River | 1927 | 99 | Poor |
| Pishkun Road over Sun River | 1916 | 40 | Poor |
| Nfsr 495 over Telegraph Creek | 1950 | 30 | Poor |
| Cpgd Access over Ten Mile Creek | 1957 | 20 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Lyndale Ave-us 12 over Great Northern Area | 2003 | 20,397 | Good |
| US 12 over RR | 1978 | 19,327 | Good |
| N Last Chance Gulc over RR | 2003 | 18,569 | Good |
| E Custer Ave over Int Custer Ave-i 15 | 2012 | 16,988 | Good |
| US 12 over Prickly Pear Creek | 1978 | 15,333 | Good |
| I 15 over Sep Boulder Ave-rr | 2016 | 14,810 | Fair |
| I 15 over Sep Boulder Ave-rr | 2017 | 14,810 | Fair |
| E Custer Ave over Helena Valley Canal | 2012 | 14,653 | Good |
| Cedar St over Int Cedar St-i 15 | 2002 | 14,368 | Fair |
| Prospect Ave-us 12 over Int Capitol-i 15 | 1961 | 12,054 | Fair |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of Montana: Montana 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.