County profile · official public datasets

Powell County, MT

113 public highway bridges tracked in the FHWA National Bridge Inventory: 25.7% rated Good, 68.1% Fair, 6.2% Poor.

113
Public bridges: 25.7%
Good condition: 6.2%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Powell County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

30th
of 56 on Poor share: 6.2%
Poor-condition share: 113
public highway bridges: 1981
avg year built

Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.

Powell County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Powell County ranks #30 of 56 Montana counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6.2%). Powell County, Montana contains 113 public highway bridges. Roughly 25.7% are rated “Good,” 68.1% “Fair,” and 6.2% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.

Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.

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

Total bridges

113

Public highway bridges in Powell County

Good condition

25.7%

29 of 113 rated 7-9

Fair condition

68.1%

77 of 113 rated 5-6

Poor condition

6.2%

7 of 113 rated 4 or below

In-state Poor-share rank

#30 of 56

Among Montana counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 113 NBI-tracked bridges by lowest applicable component rating.

Good

25.7% (29)

Fair

68.1% (77)

Poor

6.2% (7)

Powell County's Poor-condition bridges carry 18,778 vehicle crossings a day

That is 8.6% of the county's reported daily bridge traffic on 6.2% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 2,683 crossings a day against 642 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.

Computed over the 113 of 113 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

41.6% of Powell County's bridges have passed the 50-year mark

47 of the 113 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 25.7% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.

Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.

One structure carries 31.5% of the county's Poor-condition bridge traffic

I 90 EB over RR, built 1973, carries 5,915 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 7-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 18,778 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

1
1910s

1
1930s

5
1940s

4
1950s

12
1960s

14
1970s

23
1980s

9
1990s

7
2000s

21
2010s

12
2020s

4

What this shows Construction peaked in the 1970s, when 23 of the county's bridges still in the inventory were built, which is 20.4% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1981) matches the Montana average (1977).

How Powell County compares with Montana's closest counties by inventory size

The 5 Montana counties nearest Powell County in number of bridges, with their condition splits. Its 6.2% Poor share is the 2nd-lowest of these 6. Its average build year of 1981 against a peer-group mean of 1979 is in line with the group.

Showing the 5 closest of 55 Montana counties eligible for comparison.

Bridge inventory size and condition shares for Powell County and the 5 Montana counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Sanders County	120	40%	52.5%	7.5%	1979
Lake County	117	57.3%	27.4%	15.4%	1995
Rosebud County	114	18.4%	76.3%	5.3%	1973
Powell County (this page)	113	25.7%	68.1%	6.2%	1981
Dawson County	109	8.3%	85.3%	6.4%	1972
Valley County	104	10.6%	76.9%	12.5%	1975

Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Powell County's. Source: FHWA National Bridge Inventory, 2024 release.

Nationwide counties with similar inventory size or average build year

Two NBI-derived peer sets for Powell County, both outside Montana so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside MT (113 bridges here).

Lake County, FL · 113 bridges
Chattooga County, GA · 113 bridges
Jersey County, IL · 113 bridges
Tipton County, IN · 113 bridges

Similar average build year

Nearest mean year-built outside MT (1981 here).

Franklin County, OH · avg 1981 · 922 bridges
Greenville County, SC · avg 1981 · 635 bridges
Montgomery County, OH · avg 1981 · 632 bridges
McLean County, IL · avg 1981 · 624 bridges

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 113 Good 29 Fair 77 Poor 7

Fair-condition bridges (77)

Sort:

Powell County Bridge Snapshot

Condition distribution

Powell County's Poor-condition bridges carry 18,778 vehicle crossings a day

41.6% of Powell County's bridges have passed the 50-year mark

One structure carries 31.5% of the county's Poor-condition bridge traffic

How Powell County compares with Montana's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

Fair-condition bridges (77)

E SAGER LANE

TROUT CREEK RD

NO DATA ENTERED

DRY GULCH RD

KOHRS ST

I 90

GOLD CREEK RD

OVANDO HELMVILLE R

YELLOWSTONE TRAIL

ROCK CREEK CATTLE

ROCK CREEK CATTLE

S FRONTAGE RD 011

S 200

S FRONTAGE RD 011

S 141

NO DATA ENTERED

BECK HILL RD

I 90

US 12

I 90

LITTLE BLACKFOOT R

RACE TRACK RD

CUT OFF RD

S 141

I 90

I 90

I 90

RIVER JUNCTION/ SC

TELEGRAPH CR RD

2864: BRAZIEL CR.

I 90

S 200

S 141

W MILWAUKEE AVE

I 90

I 90

I 90

S FRONTAGE RD 011

I 90

OVANDO HELMVILLE R

US 12

US 12

N.FK BLACKFT RD

N.FK BLACKFT RD

C.WOOD LAKES RD

I 90

I 90

I 90 EB

I 90 WB

I 90

Related