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

IRR - I 90

Unknown

Over: INT DUNMORE

5.6M N CROW AGENCY, Big Horn, MT

Built 1959 ADT: 100

IRR - I 90

Unknown

Over: INT CROW AGENCY

CROW AGENCY, Big Horn, MT

Built 1959 ADT: 100

IRR - I 90

Unknown

Over: INT CROW AGENCY

CROW AGENCY, Big Horn, MT

Built 1959 ADT: 100

IRR - I 90

Unknown

Over: INT GARRYOWEN

5.6M S CROW AGENCY, Big Horn, MT

Built 1976 ADT: 944

IRR - I 90

Unknown

Over: INT GARRYOWEN

5.6M S CROW AGENCY, Big Horn, MT

Built 1976 ADT: 944

IRR - I 90

Unknown

Over: SEP RENO CREEK ROAD

8.7M S CROW AGENCY, Big Horn, MT

Built 1980 ADT: 100

IRR - I 90

Unknown

Over: SEP RENO CREEK ROAD

8.7M S CROW AGENCY, Big Horn, MT

Built 1980 ADT: 100

IRR - I 90

Unknown

Over: SEP COUNTY ROAD

10.5M N LODGE GRASS, Big Horn, MT

Built 1980 ADT: 100

IRR - I 90

Unknown

Over: SEP COUNTY ROAD

10.5M N LODGE GRASS, Big Horn, MT

Built 1980 ADT: 100

IRR - I 90

Unknown

Over: INT LODGE GRASS

LODGE GRASS, Big Horn, MT

Built 1980 ADT: 100

IRR - I 90

Unknown

Over: INT LODGE GRASS

LODGE GRASS, Big Horn, MT

Built 1980 ADT: 100

IRR - I 90

Unknown

Over: SEP LOCAL ROAD

1.9M S LODGE GRASS, Big Horn, MT

Built 1985 ADT: 100

IRR - I 90

Unknown

Over: SEP LOCAL ROAD

1.9M S LODGE GRASS, Big Horn, MT

Built 1985 ADT: 100

IRR - I 90

Unknown

Over: INT WYOLA-S 457

WYOLA, Big Horn, MT

Built 1985 ADT: 80

IRR - I 90

Unknown

Over: INT WYOLA-S 457

WYOLA, Big Horn, MT

Built 1985 ADT: 80

IRR - I 90

Unknown

Over: INT ABERDEEN

ABERDEEN, Big Horn, MT

Built 1985 ADT: 126

IRR - I 90

Unknown

Over: INT ABERDEEN

ABERDEEN, Big Horn, MT

Built 1985 ADT: 126

FLY CREEK RD

Unknown

Over: INT BALLANTINE-I 90 003

16M W HARDIN, Big Horn, MT

Built 1972 ADT: 3,688

N TORSKE OVERPASS

Unknown

Over: SEP I 90 00

3M NW HARDIN, Big Horn, MT

Built 1971 ADT: 3,688

RANCH ACCESS OP

Unknown

Over: SEP I-90 001

2M S ABERDEEN, Big Horn, MT

Built 1985 ADT: 3,953

IRR - US 212

Unknown

Over: INT CUSTER BATLFLD I 90

1M S CROW AGENCY, Big Horn, MT

Built 1959 ADT: 2,439

IRR-S 47-3RD ST E

Unknown

Over: INT E HARDIN I 90

HARDIN-3RD ST E, Big Horn, MT

Built 1971 ADT: 4,249

IRR-S 47

Unknown

Over: INT W HARDIN I 90

HARDIN-N CRAWFORD AVE, Big Horn, MT

Built 1970 ADT: 3,688

US 287

Unknown

Over: RR

TOSTON, Broadwater, MT

Built 2020 ADT: 100

US 287

Unknown

Over: INT THREE FORKS I 90

3M W THREE FORKS, Broadwater, MT

Built 2012 ADT: 8,465

I 15

Unknown

Over: INT DEARBORN-MISSOURI R

6M N CRAIG, Cascade, MT

Built 1971 ADT: 100

I 15

Unknown

Over: INT DEARBORN-MISSOURI R

6M N CRAIG, Cascade, MT

Built 1971 ADT: 100

I 15

Unknown

Over: MISSOURI RIVER-LOCAL

7M N CRAIG, Cascade, MT

Built 1971 ADT: 50

I 15

Unknown

Over: MISSOURI RIVER-LOCAL

7M N CRAIG, Cascade, MT

Built 1971 ADT: 100

I 15

Unknown

Over: INT HARDY-HARDY CREEK

7M S CASCADE, Cascade, MT

Built 1968 ADT: 314

I 15

Unknown

Over: INT HARDY-HARDY CREEK

7M S CASCADE, Cascade, MT

Built 1968 ADT: 314

I 15

Unknown

Over: SEP TINTINGER

5M S CASCADE, Cascade, MT

Built 1961 ADT: 100

I 15

Unknown

Over: SEP TINTINGER

5M S CASCADE, Cascade, MT

Built 1978 ADT: 100

I 15

Unknown

Over: SEP OLD US 91

3M S CASCADE, Cascade, MT

Built 1961 ADT: 314

I 15

Unknown

Over: SEP OLD US 91

3M S CASCADE, Cascade, MT

Built 1978 ADT: 314

I 15

Unknown

Over: INT S CASCADE

CASCADE, Cascade, MT

Built 1961 ADT: 100

I 15

Unknown

Over: INT S CASCADE

CASCADE, Cascade, MT

Built 1978 ADT: 100

I 15

Unknown

Over: INT N CASCADE

CASCADE, Cascade, MT

Built 1961 ADT: 100

I 15

Unknown

Over: INT N CASCADE

CASCADE, Cascade, MT

Built 1977 ADT: 100

I 15

Unknown

Over: INT ULM

ULM, Cascade, MT

Built 1958 ADT: 177

I 15

Unknown

Over: INT ULM

ULM, Cascade, MT

Built 1969 ADT: 177

I 15

Unknown

Over: SEP COUNTY ROAD

3M N ULM, Cascade, MT

Built 1969 ADT: 100

I 15

Unknown

Over: SEP COUNTY ROAD

3M N ULM, Cascade, MT

Built 1969 ADT: 100

I 15

Unknown

Over: SEP 5TH AVE SW

GREAT FALLS, Cascade, MT

Built 1967 ADT: 640

I 15

Unknown

Over: SEP 5TH AVE SW

GREAT FALLS, Cascade, MT

Built 1967 ADT: 640

I 15

Unknown

Over: INT EMERSON JCT-RR

1M N GREAT FALLS, Cascade, MT

Built 1967 ADT: 6,717

I 15

Unknown

Over: INT EMERSON JCT-RR

1M N GREAT FALLS, Cascade, MT

Built 1967 ADT: 6,717

I 15

Unknown

Over: INT MANCHESTER

4M S VAUGHN, Cascade, MT

Built 1960 ADT: 100

I 15

Unknown

Over: INT MANCHESTER

4M S VAUGHN, Cascade, MT

Built 1960 ADT: 100

I 15

Unknown

Over: SEP NEUMAN SCH RD

2M N VAUGHN, Cascade, MT

Built 1972 ADT: 100

Showing 51-100 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.