Big Horn County, MT

136 public highway bridges

Big Horn County Bridge Snapshot

Big Horn County, Montana contains 136 public highway bridges in the FHWA National Bridge Inventory. Roughly 25% are rated “Good,” 49.3% “Fair,” 5.1% “Poor,” and 5.1% 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.

136

Total Bridges

25%

Good

5.1%

Poor

5.1%

Structurally Deficient

Condition Distribution

Good

25% (34)

Fair

49.3% (67)

Poor

5.1% (7)

SD

5.1% (7)

All Bridges (136)

Sort:

I 90

Over: INT TOLUCA COUNTY ROAD

11.2M W HARDIN, Big Horn, MT

Built 1972 ADT: 100

I 90

Over: INT TOLUCA COUNTY ROAD

11.2M W HARDIN, Big Horn, MT

Built 1972 ADT: 100

IRR - I 90

Over: SARPY ROAD-S 384

1.2M E HARDIN, Big Horn, MT

Built 1971 ADT: 511

IRR - I 90

Over: SARPY ROAD-S 384

1.2M E HARDIN, Big Horn, MT

Built 1971 ADT: 511

IRR - I 90

Over: INT DUNMORE

5.6M N CROW AGENCY, Big Horn, MT

Built 1959 ADT: 100

IRR - I 90

Over: INT DUNMORE

5.6M N CROW AGENCY, Big Horn, MT

Built 1959 ADT: 100

IRR - I 90

Over: INT CROW AGENCY

CROW AGENCY, Big Horn, MT

Built 1959 ADT: 100

IRR - I 90

Over: INT CROW AGENCY

CROW AGENCY, Big Horn, MT

Built 1959 ADT: 100

IRR - I 90

Over: INT GARRYOWEN

5.6M S CROW AGENCY, Big Horn, MT

Built 1976 ADT: 944

IRR - I 90

Over: INT GARRYOWEN

5.6M S CROW AGENCY, Big Horn, MT

Built 1976 ADT: 944

IRR - I 90

Over: SEP RENO CREEK ROAD

8.7M S CROW AGENCY, Big Horn, MT

Built 1980 ADT: 100

IRR - I 90

Over: SEP RENO CREEK ROAD

8.7M S CROW AGENCY, Big Horn, MT

Built 1980 ADT: 100

IRR - I 90

Over: SEP COUNTY ROAD

10.5M N LODGE GRASS, Big Horn, MT

Built 1980 ADT: 100

IRR - I 90

Over: SEP COUNTY ROAD

10.5M N LODGE GRASS, Big Horn, MT

Built 1980 ADT: 100

IRR - I 90

Over: INT LODGE GRASS

LODGE GRASS, Big Horn, MT

Built 1980 ADT: 100

IRR - I 90

Over: INT LODGE GRASS

LODGE GRASS, Big Horn, MT

Built 1980 ADT: 100

IRR - I 90

Over: SEP LOCAL ROAD

1.9M S LODGE GRASS, Big Horn, MT

Built 1985 ADT: 100

IRR - I 90

Over: SEP LOCAL ROAD

1.9M S LODGE GRASS, Big Horn, MT

Built 1985 ADT: 100

IRR - I 90

Over: INT WYOLA-S 457

WYOLA, Big Horn, MT

Built 1985 ADT: 80

IRR - I 90

Over: INT WYOLA-S 457

WYOLA, Big Horn, MT

Built 1985 ADT: 80

IRR - I 90

Over: INT ABERDEEN

ABERDEEN, Big Horn, MT

Built 1985 ADT: 126

IRR - I 90

Over: INT ABERDEEN

ABERDEEN, Big Horn, MT

Built 1985 ADT: 126

FLY CREEK RD

Over: INT BALLANTINE-I 90 003

16M W HARDIN, Big Horn, MT

Built 1972 ADT: 3,688

N TORSKE OVERPASS

Over: SEP I 90 00

3M NW HARDIN, Big Horn, MT

Built 1971 ADT: 3,688

RANCH ACCESS OP

Over: SEP I-90 001

2M S ABERDEEN, Big Horn, MT

Built 1985 ADT: 3,953

IRR - US 212

Over: INT CUSTER BATLFLD I 90

1M S CROW AGENCY, Big Horn, MT

Built 1959 ADT: 2,439

IRR-S 47-3RD ST E

Over: INT E HARDIN I 90

HARDIN-3RD ST E, Big Horn, MT

Built 1971 ADT: 4,249

IRR-S 47

Over: INT W HARDIN I 90

HARDIN-N CRAWFORD AVE, Big Horn, MT

Built 1970 ADT: 3,688

COUNTY ROAD 143

Over: UNNAMED CREEK 059

34M E DECKER, Big Horn, MT

Built 1950 Load: 6.4 t ADT: 100

UPPER RD

Over: TWO LEGGIN`S CANAL 005

8M NW HARDIN, Big Horn, MT

Built 1950 Load: 7.3 t ADT: 100

IRR - I 90

Over: BIGHORN RIVER

HARDIN, Big Horn, MT

Built 1971 Load: 12.6 t ADT: 4,249

IRR BIA RTE 14

Over: BIG SHOULDER CREEK

7.2KM SOUTH OF CROW AGNCY, Big Horn, MT

Built 1963 Load: 14.0 t ADT: 440

IRR - I 90

Over: OWL CREEK

2.5M S LODGE GRASS, Big Horn, MT

Built 1985 Load: 15.4 t ADT: 1,978

PINE RIDGE RD

Over: TWO LEGGIN`S CANAL 014

4M NW HARDIN, Big Horn, MT

Built 1993 Load: 15.4 t ADT: 100

SARPY BASIN RD

Over: E FORK SARPY CREEK 028

30M E HARDIN, Big Horn, MT

Built 1971 Load: 16.3 t ADT: 100

BALA ST

Over: LITTLE BIGHORN RIVER 069

CROW AGENCY, Big Horn, MT

Built 1958 Load: 20.0 t ADT: 100

IRR - S 313

Over: INDIAN SERVICE CANAL

10M SW ST XAVIER, Big Horn, MT

Built 1962 Load: 20.0 t ADT: 500

IRR - I 90

Over: LITTLE BIGHORN RIVER

8M S CROW AGENCY, Big Horn, MT

Built 1956 Load: 20.4 t ADT: 2,055

LITTLE HORN RD

Over: LITTLE BIGHORN RIVER 072

8M SW WYOLA, Big Horn, MT

Built 1952 Load: 20.8 t ADT: 243

IRR BIA RTE 16

Over: LODGE GRASS CREEK

AT LODGE GRASS, Big Horn, MT

Built 1962 Load: 21.8 t ADT: 300

IRR - I 90

Over: LITTLE BIGHORN RIVER

2.5M S CROW AGENCY, Big Horn, MT

Built 1956 Load: 23.6 t ADT: 2,439

IRR - S 314

Over: ROSEBUD CREEK

11M SW BUSBY, Big Horn, MT

Built 1983 Load: 23.6 t ADT: 386

SARPY CREEK RD

Over: LITTLE BIGHORN RIVER

3M E HARDIN, Big Horn, MT

Built 1962 Load: 23.6 t ADT: 511

IRR BIA RTE 91

Over: ROTTEN GRASS CREEK

0.8 KM SW OF ST. XAVIER, Big Horn, MT

Built 1970 Load: 24.5 t ADT: 350

IRR BIA RTE 205

Over: LITTLE BIG HORN RIVER

0.4KM NW OF JCT 205 & 418, Big Horn, MT

Built 1993 Load: 24.5 t ADT: 80

IRR - S 313

Over: BIGHORN RIVER

7M SW HARDIN, Big Horn, MT

Built 1958 Load: 24.5 t ADT: 1,049

SARPY BASIN RD

Over: SARPY CREEK 033

24M E HARDIN, Big Horn, MT

Built 1981 Load: 25.3 t ADT: 100

I 90

Over: RR

14.9M W HARDIN, Big Horn, MT

Built 1972 Load: 25.4 t ADT: 3,688

I 90

Over: RR

14.9M W HARDIN, Big Horn, MT

Built 1972 Load: 25.4 t ADT: 3,688

IRR - I 90

Over: LITTLE BIGHORN RIVER

2.5M S CROW AGENCY, Big Horn, MT

Built 1976 Load: 25.4 t ADT: 2,439

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 5, 2026