Carbon County, MT

77 public highway bridges

Carbon County Bridge Snapshot

Carbon County, Montana contains 77 public highway bridges in the FHWA National Bridge Inventory. Roughly 33.8% are rated “Good,” 61% “Fair,” 5.2% “Poor,” and 5.2% are classified as structurally deficient — the federal designation for spans whose deck, superstructure, or substructure has been rated 4 or below on the 0–9 NBI scale. Structurally deficient does not mean unsafe to cross; it means the bridge is on the priority list for repair or replacement.

Inspections in MT are conducted by certified engineers from the state Department of Transportation on a 24-month cycle, and results are reported back to the FHWA each spring. The list below shows every NBI-tracked bridge in the county, sorted by inventory load rating. Use the “Sort by” controls to surface the lowest-rated spans first, and click any row for full inspection history, traffic counts, and condition trends.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

77

Total Bridges

33.8%

Good

5.2%

Poor

5.2%

Structurally Deficient

Condition Distribution

Good

33.8% (26)

Fair

61% (47)

Poor

5.2% (4)

SD

5.2% (4)

All Bridges (77)

Sort:

CHERRY SPRINGS RD

Over: CLEAR CREEK 062

1M E ROBERTS, Carbon, MT

Built 1942 ADT: 100

RED LODGE CR RD

Over: VOLNEY CREEK 015

13M SW BOYD, Carbon, MT

Built 1991 Load: 4.5 t ADT: 100

BLUEWATER RD

Over: BLUEWATER CREEK 038

3M SE FROMBERG, Carbon, MT

Built 1915 Load: 6.4 t ADT: 100

BOYD COONEY DAM RD

Over: RED LODGE CREEK 013

COONEY RESERVOIR DAM, Carbon, MT

Built 1991 Load: 14.5 t ADT: 564

2-LANE ROAD

Over: WEST FORK ROCK CREEK

8 MILES WEST OF RED LODGE, Carbon, MT

Built 1965 Load: 15.2 t ADT: 50

1-LANE ROAD

Over: WEST ROSEBUD CREEK

9 MILES SW OF ROSCOE, Carbon, MT

Built 1959 Load: 16.2 t ADT: 50

1-LANE ROAD

Over: WEST FORK ROCK CREEK

11 MILES W. OF RED LODGE, Carbon, MT

Built 1956 Load: 17.5 t ADT: 50

E ROSEBUD RD

Over: EAST ROSEBUD CREEK 017

ROSCOE, Carbon, MT

Built 2010 Load: 18.5 t ADT: 76

LONE TREE RD

Over: RED LODGE CREEK 045

1M NW BOYD, Carbon, MT

Built 1972 Load: 19.8 t ADT: 100

BOYD COONEY DAM RD

Over: ROCK CREEK 027

1M W BOYD, Carbon, MT

Built 1973 Load: 21.7 t ADT: 564

E ROSEBUD RD

Over: EAST ROSEBUD CREEK 018

2M SW ROSCOE, Carbon, MT

Built 1993 Load: 21.7 t ADT: 76

1-LANE ROAD

Over: MAIN FORK ROCK CREEK

NO DATA ENTERED, Carbon, MT

Built 1952 Load: 22.0 t ADT: 50

S 78 FH 83

Over: EAST ROSEBUD CREEK

ROSCOE, Carbon, MT

Built 1959 Load: 22.7 t ADT: 478

NO DATA ENTERED

Over: LAKE FORK ROCK CREEK

NO DATA ENTERED, Carbon, MT

Built 1952 Load: 23.3 t ADT: 50

BRIDGER FROMBERG R

Over: BLUEWATER CREEK 001

2M SE FROMBERG, Carbon, MT

Built 1913 Load: 24.5 t ADT: 218

LOWER RIVER RD

Over: BLUEWATER CREEK 002

1M SE FROMBERG, Carbon, MT

Built 1932 Load: 24.5 t ADT: 100

US 310

Over: ROCK CREEK

ROCKVALE, Carbon, MT

Built 1934 Load: 24.5 t ADT: 5,030

S 72

Over: CLARKS FORK YELLOWSTONE

4M NE BELFRY, Carbon, MT

Built 2011 Load: 25.4 t ADT: 1,722

1-LANE ROAD

Over: LAKE FORK ROCK CREEK

NO DATA ENTERED, Carbon, MT

Built 1952 Load: 25.9 t ADT: 50

S MAIN ST

Over: ROCK CREEK 046

JOLIET, Carbon, MT

Built 1987 Load: 26.3 t ADT: 891

RIVERVIEW LN

Over: CLARKS FK YELLOWSTNE 007

2M S BELFRY, Carbon, MT

Built 1981 Load: 26.3 t ADT: 100

FOX EAST BENCH RD

Over: ROCK CREEK 025

FOX, Carbon, MT

Built 2006 Load: 26.9 t ADT: 100

GIBSON RD

Over: ROCK CREEK 029

1M E ROCKVALE, Carbon, MT

Built 1979 Load: 26.9 t ADT: 31

19TH STREET

Over: ROCK CREEK 059

RED LODGE-19TH ST, Carbon, MT

Built 2012 Load: 26.9 t ADT: 359

VOLNEY CREEK RD

Over: RED LODGE CREEK 042

6M SE ROSCOE, Carbon, MT

Built 1930 Load: 27.2 t ADT: 100

US 310

Over: CLARKS FK YELLOWSTONE

2M S BRIDGER, Carbon, MT

Built 1971 Load: 28.1 t ADT: 2,245

DUTCH LN

Over: SILVERTIP CREEK 060

1M NE BELFRY, Carbon, MT

Built 2006 Load: 30.8 t ADT: 100

US 310

Over: BRIDGER CREEK

2M S BRIDGER, Carbon, MT

Built 1971 Load: 31.8 t ADT: 2,245

S 72

Over: CLARKS FORK YELLOWSTONE

5M S BELFRY, Carbon, MT

Built 1970 Load: 31.8 t ADT: 1,498

BOYD COONEY DAM RD

Over: COONEY RES SPILLWAY 014

7M W BOYD, Carbon, MT

Built 1982 Load: 32.7 t ADT: 564

RED LODGE CR RD

Over: E RED LODGE CREEK 010

8M W ROBERTS, Carbon, MT

Built 1970 Load: 32.7 t ADT: 100

TWO MILE BRIDGE RD

Over: ROCK CREEK 024

2M N RED LODGE, Carbon, MT

Built 1982 Load: 32.7 t ADT: 100

JOLIET FROMBERG RD

Over: ELBOW CREEK 035

2M SE JOLIET, Carbon, MT

Built 1979 Load: 32.7 t ADT: 173

CARBON AVE

Over: ROCK CREEK 026

1M E ROBERTS, Carbon, MT

Built 1982 Load: 32.7 t ADT: 100

E PRYOR RD

Over: CLARKS FK YELLOWSTNE 056

E EDGAR, Carbon, MT

Built 1980 Load: 32.7 t ADT: 411

E BRIDGER RD

Over: CLARKS FK YELLOWSTNE 055

E BRIDGER, Carbon, MT

Built 1980 Load: 32.7 t ADT: 258

GOLDEN LN

Over: CLARKS FK YELLOWSTNE 008

6M SW BRIDGER, Carbon, MT

Built 1981 Load: 32.7 t ADT: 100

US 212

Over: ROCK CREEK

1M W JOLIET, Carbon, MT

Built 1974 Load: 32.7 t ADT: 3,282

S 72

Over: CLARKS FORK YELLOWSTONE

1M N BELFRY, Carbon, MT

Built 2013 Load: 33.6 t ADT: 1,722

WILLOW CREEK RD

Over: WILLOW CREEK 061

7M SW ROBERTS, Carbon, MT

Built 1942 Load: 34.3 t ADT: 100

NO DATA ENTERED

Over: WEST FORK ROCK CREEK

NO DATA ENTERED, Carbon, MT

Built 1972 Load: 36.3 t ADT: 50

CHANCE RD

Over: CLARKS FK YELLOWSTNE 004

8M S BELFRY, Carbon, MT

Built 2004 Load: 36.3 t ADT: 100

US 310

Over: RR

16M SE BRIDGER, Carbon, MT

Built 2001 Load: 37.2 t ADT: 1,513

ACCESS ROAD

Over: LAYOUT CREEK

FROM N.P. VISITOR CENTER,, Carbon, MT

Built 1983 Load: 38.1 t ADT: 23

1-LANE ROAD

Over: SOUTH FORK SPRING CREEK

8 MILES SW OF RED LODGE, Carbon, MT

Built 1979 Load: 39.9 t ADT: 50

RED LODGE CR RD

Over: RED LODGE CREEK 012

11M SW BOYD, Carbon, MT

Built 2005 Load: 49.5 t ADT: 100

LESLIE RD

Over: ELBOW CREEK 036

2M SW EDGAR, Carbon, MT

Built 1913 Load: 54.4 t ADT: 100

East Side Road

Over: Rock Creek

4M S RED LODGE, Carbon, MT

Built 2023 ADT: 100

East Side Road

Over: Rock Creek

7M S Red Lodge, Carbon, MT

Built 2023 ADT: 100

Meeteetse Trail

Over: Rock Creek

1M SE of Red Lodge, Carbon, MT

Built 2023 ADT: 100

Read our methodology — how this data is sourced, computed, and verified.

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Data sourced from official U.S. government datasets. See our methodology for details. Retrieved and formatted by PlainBridges Editorial

Reviewed byPlainbridges Editorial, Plain Bridges Editorial Team · June 6, 2026