Dewey County Bridge Report Card

Dewey County scores 59 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

F59 / 100

Local infrastructure snapshot

Dewey County, South Dakota

Dewey County has 27 bridges in the National Bridge Inventory, with 4 rated poor and 1 rated scour-critical. Its poor-condition share of 14.8% is at or below the 16.1% statewide average. Poor-condition bridges carry about 458 daily vehicle crossings.

27Total Bridges

4Poor (14.8%)

8Fair (29.6%)

1Scour-Critical

Quote-Ready Local Facts

14.8%of county bridges are in poor condition, compared with 16.1% statewide and 6.7% nationally.

458daily vehicle crossings are on poor-condition bridges in the county.

1bridges are rated scour-critical, or 3.7% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Dewey County a Bridge Condition Exposure Score of 59/100 (F). The county has 27 bridges in the National Bridge Inventory, including 4 in poor condition and 1 rated scour-critical. Poor-condition bridges carry about 458 daily vehicle crossings. Poor condition does not mean unsafe; bridges judged unsafe are closed or restricted by transportation agencies.

Download all county report-card scores as CSV.

How the Score Breaks Down

Factor	Weight	County Value	Penalty
Poor-condition bridge share	40	14.8%	29.6
Poor-condition traffic exposure	25	5.3% of measured traffic	4.0
Scour-critical bridge share	20	3.7%	7.4
Average age vs national baseline	10	40 years vs 48 nationally	0.0
Traffic-data completeness	5	8,606 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	14.8%
State Poor-Condition Share	16.1%
National Poor-Condition Share	6.7%
County Scour-Critical Share	3.7%
Average Bridge Age	40 years
Poor-Condition Traffic Exposure	458 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeIRR BIA RTE 2 over Red Water Creek — 180 vehicles/day Oldest Listed BridgeIRR State Park RD over Little Moreau Rv — built in 1950 All County BridgesBrowse every bridge record in Dewey County.

Top Bridges to Watch in Dewey County

Bridge	Reason	Condition	Daily Traffic	Year Built
Fas 6247 over Bear Creek	Poor condition + traffic exposure	Poor	103	1960
IRR BIA RTE 2 over Red Water Creek	Poor condition + traffic exposure	Poor	180	1961
IRR BIA RTE 7 over Virgin Creek	Poor condition + traffic exposure	Poor	105	1961
IRR BIA RTE 7 over No Mouth Creek	Poor condition + traffic exposure	Poor	70	1960
IRR Us212 over Little Bear Ck	High traffic	Good	1,291	2023
IRR Sd020 over Ck	High traffic	Good	890	1997
IRR Sd020 over Ck	High traffic	Good	890	1997
IRR Sd063 over Moreau Rv	High traffic	Fair	717	1971
IRR Us212 over Virgin Ck	High traffic	Good	601	1988
IRR Us212 over Virgin Ck	High traffic	Good	601	1990

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.