Harding County Bridge Report Card
Harding County scores 79 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.
Harding County, South Dakota
Harding County has 49 bridges in the National Bridge Inventory, with 1 rated poor and 4 rated scour-critical. Its poor-condition share of 2.0% is at or below the 16.1% statewide average. Poor-condition bridges carry about 60 daily vehicle crossings.
Quote-Ready Local Facts
Copyable Facts for Reporters
BridgeLookup.com gives Harding County a Bridge Condition Exposure Score of 79/100 (C). The county has 49 bridges in the National Bridge Inventory, including 1 in poor condition and 4 rated scour-critical. Poor-condition bridges carry about 60 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 | 2.0% | 4.1 |
| Poor-condition traffic exposure | 25 | 0.4% of measured traffic | 0.3 |
| Scour-critical bridge share | 20 | 8.2% | 16.3 |
| Average age vs national baseline | 10 | 40 years vs 48 nationally | 0.0 |
| Traffic-data completeness | 5 | 16,315 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 | 2.0% |
| State Poor-Condition Share | 16.1% |
| National Poor-Condition Share | 6.7% |
| County Scour-Critical Share | 8.2% |
| Average Bridge Age | 40 years |
| Poor-Condition Traffic Exposure | 60 vehicles/day |
Bridges to Watch
Top Bridges to Watch in Harding County
| Bridge | Reason | Condition | Daily Traffic | Year Built |
|---|---|---|---|---|
| Old HWY 85 over Sheep Ck | Poor condition + traffic exposure | Poor | 60 | 1936 |
| Us085 over Buffalo Ck | Scour-critical foundation rating | Fair | 1,330 | 1964 |
| Sd079 over Ck | Scour-critical foundation rating | Good | 364 | 1962 |
| Sd079 over North Fork Grand Rv | Scour-critical foundation rating | Fair | 364 | 1966 |
| Sd079 over Moreau Rv | Scour-critical foundation rating | Fair | 356 | 1964 |
| Us085 over South Fork Grand Rv | High traffic | Fair | 1,484 | 1963 |
| Us085 over Jones Ck | High traffic | Fair | 1,248 | 1960 |
| Us085 over Bull Ck | High traffic | Fair | 1,248 | 1960 |
| Us085 over Sheep Ck | High traffic | Fair | 1,248 | 1963 |
| Us085 over North Br Moreau Rv | High traffic | Fair | 1,190 | 1974 |
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.