Big Horn County Bridge Report Card
Big Horn County scores 89 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.
Big Horn County, Montana
Big Horn County has 133 bridges in the National Bridge Inventory, with 5 rated poor and 2 rated scour-critical. Its poor-condition share of 3.8% is at or below the 7.4% statewide average. Poor-condition bridges carry about 794 daily vehicle crossings.
Quote-Ready Local Facts
Copyable Facts for Reporters
BridgeLookup.com gives Big Horn County a Bridge Condition Exposure Score of 89/100 (B). The county has 133 bridges in the National Bridge Inventory, including 5 in poor condition and 2 rated scour-critical. Poor-condition bridges carry about 794 daily vehicle crossings. Poor condition does not mean unsafe; bridges judged unsafe are closed or restricted by transportation agencies.
How the Score Breaks Down
| Factor | Weight | County Value | Penalty |
|---|---|---|---|
| Poor-condition bridge share | 40 | 3.8% | 7.5 |
| Poor-condition traffic exposure | 25 | 0.4% of measured traffic | 0.3 |
| Scour-critical bridge share | 20 | 1.5% | 3.0 |
| Average age vs national baseline | 10 | 47 years vs 48 nationally | 0.0 |
| Traffic-data completeness | 5 | 183,815 measured daily crossings | 0.0 |
Score = 100 minus weighted penalties. The score is a comparative research signal, not an official safety rating. Read the full methodology.
County Comparisons
| County Poor-Condition Share | 3.8% |
| State Poor-Condition Share | 7.4% |
| National Poor-Condition Share | 6.7% |
| County Scour-Critical Share | 1.5% |
| Average Bridge Age | 47 years |
| Poor-Condition Traffic Exposure | 794 vehicles/day |
Bridges to Watch
Top Bridges to Watch in Big Horn County
| Bridge | Reason | Condition | Daily Traffic | Year Built |
|---|---|---|---|---|
| Old HWY 87 over Two Leggins Canal 0 | Poor condition + traffic exposure | Poor | 564 | 1931 |
| Battlefield Road over Medicine Tail Coulee | Poor condition + traffic exposure | Poor | 150 | 1938 |
| Soap Creek RD over Big Horn Canal 009 | Poor condition + traffic exposure | Poor | 63 | 1946 |
| IRR BIA RTE 205 over Upper Lodge Grass Creek | Poor condition + traffic exposure | Poor | 12 | 1994 |
| IRR BIA RTE 226 over Black Canyon Creek | Poor condition + traffic exposure | Poor | 5 | 1965 |
| Sarpy Creek RD over Little Bighorn River | Scour-critical foundation rating | Fair | 514 | 1962 |
| Irrc0unty Road 223 over Soap Creek 020 | Scour-critical foundation rating | Fair | 100 | 1980 |
| I 90 over Irrigation Canal | High traffic | Fair | 8,516 | 1971 |
| Irr-s 47 over Int W Hardin I 90 | High traffic | Fair | 5,396 | 1970 |
| IRR - I 90 over Int Dunmore | High traffic | Fair | 4,473 | 1959 |
Important safety note
Poor condition does not mean a bridge is unsafe. It means at least one major component has significant deterioration and the bridge is a priority for maintenance, repair, or replacement. Bridges judged unsafe are closed or restricted by transportation agencies.