Missoula County Bridge Report Card

Missoula County scores 78 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

C78 / 100

Local infrastructure snapshot

Missoula County, Montana

Missoula County has 206 bridges in the National Bridge Inventory, with 15 rated poor and 5 rated scour-critical. Its poor-condition share of 7.3% is at or below the 7.4% statewide average. Poor-condition bridges carry about 29,858 daily vehicle crossings.

206Total Bridges

15Poor (7.3%)

125Fair (60.7%)

5Scour-Critical

Quote-Ready Local Facts

7.3%of county bridges are in poor condition, compared with 7.4% statewide and 6.7% nationally.

29,858daily vehicle crossings are on poor-condition bridges in the county.

5bridges are rated scour-critical, or 2.4% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Missoula County a Bridge Condition Exposure Score of 78/100 (C). The county has 206 bridges in the National Bridge Inventory, including 15 in poor condition and 5 rated scour-critical. Poor-condition bridges carry about 29,858 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	7.3%	14.6
Poor-condition traffic exposure	25	3.2% of measured traffic	2.4
Scour-critical bridge share	20	2.4%	4.9
Average age vs national baseline	10	49 years vs 48 nationally	0.6
Traffic-data completeness	5	927,867 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	7.3%
State Poor-Condition Share	7.4%
National Poor-Condition Share	6.7%
County Scour-Critical Share	2.4%
Average Bridge Age	49 years
Poor-Condition Traffic Exposure	29,858 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeI 90 over Int Reserve Street — 13,664 vehicles/day Oldest Listed BridgeSunset Hill RD over Blackfoot River 088 — built in 1907 All County BridgesBrowse every bridge record in Missoula County.

Top Bridges to Watch in Missoula County

Bridge	Reason	Condition	Daily Traffic	Year Built
I 90 over Int Reserve Street	Poor condition + traffic exposure	Poor	13,664	1966
I 90 over Clark Fork River	Poor condition + traffic exposure	Poor	9,168	1964
Lolo ST over Rattlesnake Creek 009	Poor condition + traffic exposure	Poor	2,363	1966
Mullan RD over Irrigation Canal	Poor condition + traffic exposure	Poor	1,635	1970
S 474 over Rr	Poor condition + traffic exposure	Poor	1,397	1959
US 12 Fh 11 over Lolo Creek	Poor condition + traffic exposure	Poor	799	1957
HWY 10 W over Ninemile Creek 035	Poor condition + traffic exposure	Poor	141	1924
HWY 10 W over Ninemile Slide 026	Poor condition + traffic exposure	Poor	141	1947
Sunset Hill RD over Blackfoot River 088	Poor condition + traffic exposure	Poor	100	1907
Boy Scout RD over Clearwater River 082	Poor condition + traffic exposure	Poor	100	1938

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.