State profile · Near median Poor share

Montana bridge safety

Condition ratings, load ratings, and Poor-condition data for every public highway bridge in Montana, based on the FHWA National Bridge Inventory.

5,122
Public bridges
28.3%
Good condition
6.7%
Poor condition

Data updated May 2026

Total Bridges

5,122

Public highway bridges in Montana

Good Condition

28.3%

1,447 bridges rated 7-9

-21.7pp vs 50% benchmark

Poor Condition

6.7%

343 bridges whose lowest applicable component is rated 0-4

-0.3pp vs national avg 7.0%

Montana vs national bridge condition

Montana - Good condition share 28.3%
National avg

Share of bridges rated 7-9 on the FHWA 0-9 scale (deck, superstructure, substructure all good).

Montana - Poor-condition share 22.3%
National avg

Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.0%.

Montana vs nearby ranks

Adjacent states by Poor-condition share (lower share = better)

States are ranked by the share of bridges whose lowest applicable component rating is 4 or below. This describes recorded condition; it does not measure funding effectiveness or live crossing safety. States here sit immediately above and below Montana on the same metric.

NC

North Carolina

6.16% top marginal rate
Structure
Progressive
Burden @ $100K
$18,901

HI

Hawaii

6.47% top marginal rate
Structure
Progressive
Burden @ $100K
$1,206
Selected

MT

Montana

6.70% top marginal rate
Structure
Progressive
Burden @ $100K
$5,122

NY

New York

6.90% top marginal rate
Structure
Progressive
Burden @ $100K
$19,132

KY

Kentucky

7.06% top marginal rate
Structure
Progressive
Burden @ $100K
$14,554

Bridges Needing Most Attention in Montana

Six lowest-condition bridges in Montana, ranked by the portal's composite display score. Inspection intervals are risk-based under current NBIS rules.

All Bridges in Montana

I 15

Unknown

Over: SEP NEUMAN SCH RD

2M N VAUGHN, Cascade, MT

Built 1972 ADT: 100

I 15

Unknown

Over: SEP GUNDERSON RD

2M S POWER, Cascade, MT

Built 1972 ADT: 100

I 15

Unknown

Over: SEP GUNDERSON RD

2M S POWER, Cascade, MT

Built 1972 ADT: 100

I 315S

Unknown

Over: INT I 15

GREAT FALLS, Cascade, MT

Built 1967 ADT: 6,889

I 315S

Unknown

Over: FAU 5225-14TH ST SW

GREAT FALLS, Cascade, MT

Built 1967 ADT: 9,271

I 315S

Unknown

Over: FAU 5225-14TH ST SW

GREAT FALLS, Cascade, MT

Built 1967 ADT: 3,395

I 315 S

Unknown

Over: FAU 5225-14TH ST SW

GREAT FALLS, Cascade, MT

Built 1997 ADT: 9,271

ANDERSON RD

Unknown

Over: INT GORDON-I 15

6M NW VAUGHN, Cascade, MT

Built 1972 ADT: 2,000

OLD ULM CASCADE RD

Unknown

Over: SEP I 15

6M NE CASCADE, Cascade, MT

Built 1977 ADT: 4,847

OLD ULM CASCADE RD

Unknown

Over: SEP I 15

3M SW ULM, Cascade, MT

Built 1970 ADT: 2,424

FRONTAGE ROAD 614

Unknown

Over: INT SEP I 15

4M SW CASCADE, Cascade, MT

Built 1978 ADT: 2,189

FRONTAGE ROAD 615

Unknown

Over: INT CANYON-I 15

11M SW CASCADE, Cascade, MT

Built 1968 ADT: 2,224

34TH ST NW

Unknown

Over: SEP 34TH ST-I 15

1M W GREAT FALLS, Cascade, MT

Built 1967 ADT: 3,244

SUN RIVER RD

Unknown

Over: SEP WEST HILL-I 15 127

GREAT FALLS, Cascade, MT

Built 1967 ADT: 5,101

US 89

Unknown

Over: INT VAUGHN-I 15

VAUGHN, Cascade, MT

Built 1960 ADT: 4,297

US 87-MT 3-MT 200

Unknown

Over: MISSOURI RIVER-U5205-RR

GREAT FALLS-10TH AVE S, Cascade, MT

Built 1983 ADT: 5,718

US 89-MT 3-MT 200

Unknown

Over: MISSOURI RIVER-U5205-RR

GREAT FALLS-10TH AVE S, Cascade, MT

Built 1951 ADT: 5,718

SMELTER AVE

Unknown

Over: 15TH ST NE

BLACK EAGLE-SMELTER AVE, Cascade, MT

Built 1963 ADT: 11,678

CENTRAL AVE W

Unknown

Over: INT CENTRAL AVE W-I 15

GREAT FALLS-CENTRAL AVE W, Cascade, MT

Built 1967 ADT: 3,244

CENTRAL AVE W

Unknown

Over: GALT AVE-RR

GREAT FALLS-CENTRAL AVE W, Cascade, MT

Built 1967 ADT: 689

CENTRAL AVE W

Unknown

Over: GALT AVE-RR

GREAT FALLS-CENTRAL AVE W, Cascade, MT

Built 1967 ADT: 689

AIRPORT DR

Unknown

Over: INT GORE HILL-I 15

1M SW GREAT FALLS, Cascade, MT

Built 1967 ADT: 3,053

I 94

Unknown

Over: INT P-23 BROADUS

SE EDGE MILES CITY, Custer, MT

Built 2019 ADT: 1,894

I 94

Unknown

Over: INT P-23 BROADUS

SE EDGE MILES CITY, Custer, MT

Built 2020 ADT: 3,788

I 94

Unknown

Over: SEP CEMETERY RD

S EDGE MILES CITY, Custer, MT

Built 1961 ADT: 689

I 94

Unknown

Over: SEP CEMETERY RD

S EDGE MILES CITY, Custer, MT

Built 1974 ADT: 689

I 94

Unknown

Over: INT DIAMOND RING

21M NE MILES CITY, Custer, MT

Built 1971 ADT: 100

I 94

Unknown

Over: INT DIAMOND RING

21M NE MILES CITY, Custer, MT

Built 1971 ADT: 100

VALLEY DR E

Unknown

Over: INT SHIRLEY-I 94 006

10M NE MILES CITY, Custer, MT

Built 1984 ADT: 2,111

FRONTAGE ROAD 005

Unknown

Over: INT RADAR BASE-I 94 004

8M SW MILES CITY, Custer, MT

Built 1961 ADT: 2,323

FRONTAGE ROAD 201

Unknown

Over: INT MOON CREEK-I 94 005

10M SW MILES CITY, Custer, MT

Built 1962 ADT: 2,323

US 94

Unknown

Over: INT W MILES CITY-I 94

3M SW MILES CITY, Custer, MT

Built 1961 ADT: 2,285

US 94

Unknown

Over: TONGUE RIVER

SW EDGE MILES CITY, Custer, MT

Built 2007 ADT: 100

US 94

Unknown

Over: INT BAKER-I 94

2M NE MILES CITY, Custer, MT

Built 1974 ADT: 2,481

I 94

Unknown

Over: COUNTY ROAD 119

15M SW GLENDIVE, Dawson, MT

Built 1973 ADT: 100

I 94

Unknown

Over: COUNTY ROAD 119

15M SW GLENDIVE, Dawson, MT

Built 1973 ADT: 100

I 94

Unknown

Over: INT CRACKER BOX ROAD

12M SW GLENDIVE, Dawson, MT

Built 1973 ADT: 100

I 94

Unknown

Over: INT CRACKER BOX ROAD

12M SW GLENDIVE, Dawson, MT

Built 1973 ADT: 100

I 94

Unknown

Over: SEP ROAD 240

1M SW GLENDIVE, Dawson, MT

Built 1976 ADT: 100

I 94

Unknown

Over: SEP ROAD 240

1M SW GLENDIVE, Dawson, MT

Built 1976 ADT: 100

I 94

Unknown

Over: INT P 98-W GLENDIVE

SW GLENDIVE, Dawson, MT

Built 1969 ADT: 94

I 94

Unknown

Over: INT P 98-W GLENDIVE

SW GLENDIVE, Dawson, MT

Built 1969 ADT: 453

I 94

Unknown

Over: INT CIRCLE-RR-7M CR

W GLENDIVE, Dawson, MT

Built 1969 ADT: 1,719

I 94

Unknown

Over: INT CIRCLE-RR-7M CR

W GLENDIVE, Dawson, MT

Built 1969 ADT: 1,719

I 94

Unknown

Over: INT P 20-SIDNEY

NW GLENDIVE, Dawson, MT

Built 1969 ADT: 3,948

I 94

Unknown

Over: INT P 20-SIDNEY

NW GLENDIVE, Dawson, MT

Built 1969 ADT: 3,948

I 94

Unknown

Over: SEP COUNTY RD 300

3M E GLENDIVE, Dawson, MT

Built 1980 ADT: 114

I 94

Unknown

Over: SEP COUNTY RD 300

3M E GLENDIVE, Dawson, MT

Built 1980 ADT: 114

I 94

Unknown

Over: INT GRIFFITH CREEK

9M E GLENDIVE, Dawson, MT

Built 1979 ADT: 100

I 94

Unknown

Over: INT GRIFFITH CREEK

9M E GLENDIVE, Dawson, MT

Built 1979 ADT: 100

Showing 101-150 of 5,122 bridges

Data sourced from the FHWA National Bridge Inventory (NBI), latest released cycle. See our methodology for details. Retrieved and formatted by PlainBridges.

Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from the FHWA National Bridge Inventory (NBI). Poor condition is an inspection-record category, not a closure or unsafe-to-cross designation. Consult the bridge owner for current status.

Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.