County profile · official public datasets

McCone County, MT

44 public highway bridges tracked in the FHWA National Bridge Inventory: 11.4% rated Good, 79.5% Fair, 9.1% Poor.

44
Public bridges: 11.4%
Good condition: 9.1%
Poor condition

The verdict

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

McCone County pairs a higher-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.

40th
of 56 on Poor share: 9.1%
Poor-condition share: 44
public highway bridges: 1967
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.

McCone County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, McCone County ranks #40 of 56 Montana counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 9.1%). McCone County, Montana contains 44 public highway bridges. Roughly 11.4% are rated “Good,” 79.5% “Fair,” and 9.1% “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

Public highway bridges in McCone County

Good condition

11.4%

5 of 44 rated 7-9

Fair condition

79.5%

35 of 44 rated 5-6

Poor condition

9.1%

4 of 44 rated 4 or below

In-state Poor-share rank

#40 of 56

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

Condition distribution

Share of 44 NBI-tracked bridges by lowest applicable component rating.

Good

11.4% (5)

Fair

79.5% (35)

Poor

9.1% (4)

McCone County's Poor-condition bridges carry 3,136 vehicle crossings a day

That is 14.2% of the county's reported daily bridge traffic on 9.1% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 784 crossings a day against 582 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 44 of 44 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

65.9% of McCone County's bridges have passed the 50-year mark

29 of the 44 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 11.4% 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 32.3% of the county's Poor-condition bridge traffic

S 200 over CEMETERY COULEE, built 1939, carries 1,012 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 4-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 3,136 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1930s

9
1950s

7
1960s

9
1970s

5
1980s

4
1990s

9
2000s

1

What this shows Construction peaked in the 1930s, when 9 of the county's bridges still in the inventory were built, which is 20.5% of those with a recorded year. That cohort is now 85 to 94 years old in the 2024 inventory. Its average build year is 1967, 10 years older than the Montana average of 1977.

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

The 5 Montana counties nearest McCone County in number of bridges, with their condition splits. Its 9.1% Poor share is the 5th-lowest of these 6. Its average build year of 1967 against a peer-group mean of 1978 is 11 years older.

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

Bridge inventory size and condition shares for McCone County and the 5 Montana counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Judith Basin County	48	56.3%	31.3%	12.5%	1979
Hill County	46	58.7%	34.8%	6.5%	1983
Prairie County	46	13%	80.4%	6.5%	1962
McCone County (this page)	44	11.4%	79.5%	9.1%	1967
Chouteau County	42	54.8%	38.1%	7.1%	1981
Carter County	41	31.7%	63.4%	4.9%	1985

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 McCone 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 McCone County, both outside Montana so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside MT (44 bridges here).

Archuleta County, CO · 44 bridges
Bacon County, GA · 44 bridges
Pulaski County, GA · 44 bridges
Rockdale County, GA · 44 bridges

Similar average build year

Nearest mean year-built outside MT (1967 here).

Los Angeles County, CA · avg 1967 · 3,547 bridges
Allegheny County, PA · avg 1967 · 1,294 bridges
Sonoma County, CA · avg 1967 · 609 bridges
Merced County, CA · avg 1967 · 528 bridges

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

All 44 Good 5 Fair 35 Poor 4

All bridges (44)

Sort:

McCone County Bridge Snapshot

Condition distribution

McCone County's Poor-condition bridges carry 3,136 vehicle crossings a day

65.9% of McCone County's bridges have passed the 50-year mark

One structure carries 32.3% of the county's Poor-condition bridge traffic

How McCone 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

All bridges (44)

S 200

S 200

S 252-HORSE CR RD

S 467-UNION RD

S 200

S 200

SUNNYSIDE RD

S 467-UNION RD

S 252-HORSE CR RD

S 467-UNION RD

WELDON RD

S 200

S 252-HORSE CR RD

S 253

S 13

S 13

S 13

S 200

S 528

NICKWALL RD

S 252-WELDON RD

S 13

S 200S

S 252-WELDON RD

S 24

S 528

S 13

WELDON RD

STATE HIGHWAY 24

S 24

IRR - S 13

IRR - S 13

S 13

IRR - S 13

S 200

S 201

VIDA EAST RD

S 13

S 13

IRR - S 13

BEAUTY CREEK RD

S 200

S 200

S 200

Related