Granite County, MT

73 public highway bridges

Granite County Bridge Snapshot

Granite County, Montana contains 73 public highway bridges in the FHWA National Bridge Inventory. Roughly 31.5% are rated “Good,” 42.5% “Fair,” 11% “Poor,” and 11% 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.

73

Total Bridges

31.5%

Good

11%

Poor

11%

Structurally Deficient

Condition Distribution

Good

31.5% (23)

Fair

42.5% (31)

Poor

11% (8)

SD

11% (8)

All Bridges (73)

Sort:

I 90

Over: INT BEARMOUTH

BEARMOUTH, Granite, MT

Built 1970 ADT: 47

I 90

Over: INT BEARMOUTH

BEARMOUTH, Granite, MT

Built 1970 ADT: 267

I 90

Over: SEP BEARMOUTH ROAD

10.5M W DRUMMOND, Granite, MT

Built 1970 ADT: 128

I 90

Over: INT W DRUMMOND

DRUMMOND, Granite, MT

Built 1966 ADT: 1,478

I 90

Over: INT W DRUMMOND

DRUMMOND, Granite, MT

Built 1966 ADT: 1,478

I 90

Over: SEP EDWARDS GULCH ROAD

DRUMMOND, Granite, MT

Built 1966 ADT: 298

I 90

Over: SEP EDWARDS GULCH ROAD

DRUMMOND, Granite, MT

Built 1966 ADT: 298

I 90

Over: INT E DRUMMOND

DRUMMOND, Granite, MT

Built 1966 ADT: 51

I 90

Over: INT E DRUMMOND

DRUMMOND, Granite, MT

Built 1966 ADT: 51

I 90

Over: SEP S-271

1.2M E DRUMMOND, Granite, MT

Built 1966 ADT: 274

I 90

Over: SEP S-271

1.2M E DRUMMOND, Granite, MT

Built 1966 ADT: 274

NO DATA ENTERED

Over: FLINT CREEK

5 MI. N. OF P-BURG ON HWY, Granite, MT

Built 2001 Load: 20.1 t ADT: 50

GRIZZLE CAMP RD

Over: RANCH CR

GRIZZLY CAMP, Granite, MT

Built 1958 Load: 20.1 t ADT: 50

UPPER ROCK CR RD

Over: STONY CREEK 011

19M W PHILLIPSBURG, Granite, MT

Built 1999 Load: 20.1 t ADT: 592

FRONTAGE ROAD 153

Over: CLARK FORK RIVER 034

14M W DRUMMOND, Granite, MT

Built 1970 Load: 20.1 t ADT: 267

NO DATA ENTERED

Over: HOGBACK CREEK

NO DATA ENTERED, Granite, MT

Built 2008 Load: 21.1 t ADT: 50

MANY GLACIER ROAD

Over: WINDY CREEK

8.8 miles west of U.S. Ro, Granite, MT

Built 1931 Load: 21.8 t ADT: 452

S 1

Over: FLINT CREEK

4M N MAXVILLE, Granite, MT

Built 1931 Load: 23.6 t ADT: 1,123

S 1

Over: FRED BURR CREEK

2M S PHILIPSBURG, Granite, MT

Built 1931 Load: 24.5 t ADT: 1,663

NO DATA ENTERED

Over: COPPER CR

AFTER COPPER CREEK CG, Granite, MT

Built 1956 Load: 24.6 t ADT: 50

I 90

Over: CLARK FORK RIVER

0.6M W BEARMOUTH, Granite, MT

Built 1970 Load: 25.4 t ADT: 11,108

S 1

Over: BOULDER CREEK

MAXVILLE, Granite, MT

Built 1986 Load: 25.4 t ADT: 1,123

NO DATA ENTERED

Over: MIDDLE FORK ROCK CR

AT JUNCTION TO MOOSE LAKE, Granite, MT

Built 1956 Load: 25.9 t ADT: 50

MULLAN RD E

Over: FLINT CREEK 001

2M S DRUMMOND, Granite, MT

Built 1998 Load: 26.3 t ADT: 100

GOLD COIN ROAD

Over: FLINT CREEK 017

13M S DRUMMOND, Granite, MT

Built 1984 Load: 26.3 t ADT: 100

MAIN ST

Over: BERGMAN SLOUGH 019

DRUMMOND-MAIN STREET, Granite, MT

Built 1934 Load: 29.9 t ADT: 544

S 1

Over: WILLOW CREEK

4M S DRUMMOND, Granite, MT

Built 1999 Load: 29.9 t ADT: 1,260

NO DATA ENTERED

Over: ROSS FORK

ROSS FORK, Granite, MT

Built 1962 Load: 30.5 t ADT: 50

NO DATA ENTERED

Over: SPILLWAY

SPILLWAY, Granite, MT

Built 1958 Load: 30.8 t ADT: 50

NO DATA ENTERED

Over: MIDDLE FORK ROCK CR

MIDDLE FORK ROCK CR, Granite, MT

Built 1965 Load: 31.1 t ADT: 40

NO DATA ENTERED

Over: WEST FORK ROCK CR

WEST FORK ROCK CR, Granite, MT

Built 1965 Load: 32.7 t ADT: 50

S 1

Over: ABANDONED RAILROAD

DRUMMOND, Granite, MT

Built 1966 Load: 32.7 t ADT: 1,329

NO DATA ENTERED

Over: GOLD CREEK

JACKSON PARK ROAD, Granite, MT

Built 1975 Load: 33.0 t ADT: 40

NO DATA ENTERED

Over: ROSS FORK

ROSS FORK, Granite, MT

Built 1961 Load: 34.0 t ADT: 40

NO DATA ENTERED

Over: MIDDLE FORK ROCK CR

BEFORE KAISER LAKE, Granite, MT

Built 1965 Load: 35.0 t ADT: 40

NO DATA ENTERED

Over: WEST FORK ROCK CR

WEST FORK ROCK CR, Granite, MT

Built 1969 Load: 35.3 t ADT: 40

NO DATA ENTERED

Over: BOWLES CR

BOWLES CR, Granite, MT

Built 1971 Load: 35.3 t ADT: 50

S 1

Over: RR

DRUMMOND, Granite, MT

Built 1966 Load: 35.4 t ADT: 1,329

NO DATA ENTERED

Over: ROSS FORK

ROSS FORK, Granite, MT

Built 1967 Load: 35.6 t ADT: 50

MARSHALL CREEK RD

Over: FLINT CREEK

1M W PHILIPSBURG, Granite, MT

Built 1956 Load: 37.2 t ADT: 345

ROCK CREEK RD

Over: RANCH CREEK 009

10M S ROCK CREEK INT, Granite, MT

Built 1977 Load: 38.1 t ADT: 592

ROAD 5156

Over: UPPER WILLOW CR

UPPER WILLOW CR, Granite, MT

Built 1968 Load: 42.1 t ADT: 40

WALBERG RANCH LN

Over: ROCK CREEK 054

25M W PHILLIPSBURG, Granite, MT

Built 1987 Load: 11.7 t ADT: 592

BLACK PINE ROAD

Over: FLINT CREEK 007

2M NW PHILLIPSBURG, Granite, MT

Built 1991 Load: 19.1 t ADT: 100

MAXVILLE RD

Over: BOULDER CREEK 014

1M S MAXVILLE, Granite, MT

Built 2012 Load: 23.7 t ADT: 100

METESH LANE

Over: FLINT CREEK 055

5M SW PHILLIPSBURG, Granite, MT

Built 2009 Load: 25.4 t ADT: 100

ROSS FORK ROAD

Over: MIDDLE FORK ROCK CR 021

15M SW PHILLIPSBURG, Granite, MT

Built 1991 Load: 27.2 t ADT: 100

MULLAN RD E

Over: FLINT CREEK OVERFLOW 084

2M S DRUMMOND, Granite, MT

Built 1998 Load: 28.1 t ADT: 100

4638: SCOTCHMAN GU

Over: UPPER WILLOW CREEK

14 mi W of MT1/US10A, Granite, MT

Built 1980 Load: 28.5 t ADT: 25

N SANDIN RANCH LN

Over: MIDDLE FORK ROCK CR 032

15M SW PHILLIPSBURG, Granite, MT

Built 2004 Load: 29.5 t ADT: 273

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