Lewis and Clark County, MT

196 public highway bridges

Lewis and Clark County Bridge Snapshot

Lewis and Clark County, Montana contains 196 public highway bridges in the FHWA National Bridge Inventory. Roughly 51.5% are rated “Good,” 30.6% “Fair,” 4.6% “Poor,” and 4.6% 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.

196

Total Bridges

51.5%

Good

4.6%

Poor

4.6%

Structurally Deficient

Condition Distribution

Good

51.5% (101)

Fair

30.6% (60)

Poor

4.6% (9)

SD

4.6% (9)

All Bridges (196)

Sort:

NFSR 233

Over: BEAVER CREEK

25.4 MI NW OF AUGUSTA, Lewis and Clark, MT

Built 1978 Load: 33.4 t ADT: 26

US 12

Over: PRICKLY PEAR CREEK

EAST HELENA, Lewis and Clark, MT

Built 1978 Load: 33.6 t ADT: 13,647

CANYON FERRY RD

Over: HELENA VALLEY CANAL

5M E HELENA, Lewis and Clark, MT

Built 2009 Load: 33.6 t ADT: 4,806

MCHUGH LN

Over: TEN MILE CREEK 087

2M N HELENA, Lewis and Clark, MT

Built 1989 Load: 33.7 t ADT: 1,882

GREEN MEADOW DR

Over: SILVER CREEK

6M N HELENA, Lewis and Clark, MT

Built 2000 Load: 34.5 t ADT: 2,548

ELK CREEK RD

Over: ELK CREEK 044

12M SE AUGUSTA, Lewis and Clark, MT

Built 2020 Load: 36.3 t ADT: 100

ELK CREEK RD

Over: ELK CREEK 045

13M SW AUGUSTA, Lewis and Clark, MT

Built 2020 Load: 36.3 t ADT: 100

ELK CREEK RD

Over: ELK CREEK 046

13M SW AUGUSTA, Lewis and Clark, MT

Built 2021 Load: 36.3 t ADT: 100

YORK RD

Over: TROUT CREEK

15M NE HELENA, Lewis and Clark, MT

Built 1982 Load: 36.3 t ADT: 470

DEARBORN CANYON RD

Over: DEARBORN RIVER 048

1M SW BEAN LAKE, Lewis and Clark, MT

Built 1982 Load: 37.2 t ADT: 117

REMINI RD

Over: TEN MILE CREEK 103

13M SW HELENA, Lewis and Clark, MT

Built 2015 Load: 37.3 t ADT: 230

RIMINI RD

Over: TEN MILE CREEK 102

12M SW HELENA, Lewis and Clark, MT

Built 2015 Load: 37.6 t ADT: 230

MILL ROAD

Over: HELENA VALLEY CANAL 082

2M NW HELENA, Lewis and Clark, MT

Built 2021 Load: 38.1 t ADT: 1,264

BARR CREEK RD

Over: WILLOW CREEK 026

8M NW AUGUSTA, Lewis and Clark, MT

Built 1991 Load: 38.1 t ADT: 100

SAWMILL CREEK ROAD

Over: SAWMILL CREEK

LINCOLN RANGER DISTRICT, Lewis and Clark, MT

Built 2013 Load: 38.9 t ADT: 40

I 15

Over: RR

2M N CRAIG, Lewis and Clark, MT

Built 1967 Load: 39.0 t ADT: 2,224

US 287

Over: ELK CREEK

AUGUSTA, Lewis and Clark, MT

Built 2008 Load: 39.0 t ADT: 436

US 287

Over: ELK CREEK OVERFLOW

AUGUSTA, Lewis and Clark, MT

Built 2008 Load: 39.0 t ADT: 436

US 287

Over: DRY CREEK

5M SE AUGUSTA, Lewis and Clark, MT

Built 2008 Load: 39.9 t ADT: 375

AUGUSTA RD

Over: MIDDLE FORK DEARBORN 010

25M S AUGUSTA, Lewis and Clark, MT

Built 2014 Load: 40.5 t ADT: 46

US 12

Over: RR

3M E HELENA, Lewis and Clark, MT

Built 1978 Load: 40.8 t ADT: 18,929

LYONS CREEK RD

Over: LYONS CREEK 157

5M S WOLF CREEK, Lewis and Clark, MT

Built 1990 Load: 41.7 t ADT: 100

WILLIAMS AVE

Over: TEN MILE CREEK 003

1M W HELENA, Lewis and Clark, MT

Built 2010 Load: 41.7 t ADT: 3,050

CANYON FERRY RD

Over: HELENA VALLEY CANAL

9M NE EAST HELENA, Lewis and Clark, MT

Built 2010 Load: 41.7 t ADT: 1,580

BLACK BEAR RD

Over: TROUT CREEK 141

YORK, Lewis and Clark, MT

Built 2000 Load: 42.6 t ADT: 100

E CUSTER AVE

Over: HELENA VALLEY CANAL

HELENA-E CUSTER AVE, Lewis and Clark, MT

Built 2012 Load: 44.5 t ADT: 13,133

I 15

Over: RR

2M N CRAIG, Lewis and Clark, MT

Built 1967 Load: 45.4 t ADT: 2,224

FIELDS GULCH ROAD

Over: POORMAN CREEK

FIELDS GULCH ROAD, Lewis and Clark, MT

Built 2013 Load: 47.0 t ADT: 20

US 12

Over: TEN MILE CREEK

5M W HELENA, Lewis and Clark, MT

Built 1988 Load: 50.8 t ADT: 4,915

S 200

Over: WILDLIFE CROSSING

6M NE LINCOLN, Lewis and Clark, MT

Built 2014 Load: 50.8 t ADT: 1,761

S 200

Over: WILDLIFE CROSSING

9M NE LINCOLN, Lewis and Clark, MT

Built 2014 Load: 50.8 t ADT: 1,761

N MONTANA AVE

Over: TEN MILE CREEK

2M N HELENA, Lewis and Clark, MT

Built 2004 Load: 51.2 t ADT: 11,526

I 15

Over: TEN MILE CREEK

4M N HELENA, Lewis and Clark, MT

Built 1962 Load: 53.5 t ADT: 6,190

I 15

Over: TEN MILE CREEK

4M N HELENA, Lewis and Clark, MT

Built 1962 Load: 53.5 t ADT: 6,190

N LAST CHANCE GULC

Over: RR

HELENA, Lewis and Clark, MT

Built 2003 Load: 55.3 t ADT: 18,187

I 15

Over: LITTLE PRICKLY PEAR CR

2M NW SEIBEN INT, Lewis and Clark, MT

Built 1965 Load: 89.8 t ADT: 4,765

I 15

Over: ROCK CREEK

3M N WOLF CREEK, Lewis and Clark, MT

Built 1967 Load: 98.0 t ADT: 4,253

LOVERS LANE

Over: ELK CREEK 041

S AUGUSTA, Lewis and Clark, MT

Built 1914 Load: 7.8 t ADT: 100

FDR #8983

Over: N FK SUN RIVER

HANNAN GULCH, Lewis and Clark, MT

Built 1927 Load: 15.9 t ADT: 99

CRAIG FRONTAGE RD

Over: MISSOURI RIVER 054

2M NE WOLF CREEK, Lewis and Clark, MT

Built 1933 Load: 20.0 t ADT: 390

NFSR 495

Over: TELEGRAPH CREEK

TELEGRAPH-TELEGRAPH, Lewis and Clark, MT

Built 1950 Load: 20.1 t ADT: 30

CPGD ACCESS

Over: TEN MILE CREEK

MOOSE CR CAMP GD., Lewis and Clark, MT

Built 1957 Load: 20.4 t ADT: 20

NFSR 9229

Over: WOOD CREEK

WOOD CREEK, Lewis and Clark, MT

Built 1967 Load: 26.2 t ADT: 50

S 200

Over: STOCKPASS

23M SW SIMMS, Lewis and Clark, MT

Built 1949 Load: 33.6 t ADT: 1,382

PISHKUN ROAD

Structurally Deficient

Over: Sun River

19 miles NW of Augusta, Lewis and Clark, MT

Built 1916 Load: 4.5 t ADT: 40

DALTON MNT RD

Structurally Deficient

Over: BLACKFOOT RIVER 095

3M W LINCOLN, Lewis and Clark, MT

Built 1956 Load: 21.8 t ADT: 111

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