County profile · official public datasets

Roosevelt County, MT

57 public highway bridges tracked in the FHWA National Bridge Inventory: 28.1% rated Good, 64.9% Fair, 7% Poor.

57
Public bridges: 28.1%
Good condition: 7%
Poor condition

The verdict

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

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

35th
of 56 on Poor share: 7%
Poor-condition share: 57
public highway bridges: 1984
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.

Roosevelt County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Roosevelt County ranks #35 of 56 Montana counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 7%). Roosevelt County, Montana contains 57 public highway bridges. Roughly 28.1% are rated “Good,” 64.9% “Fair,” and 7% “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 Roosevelt County

Good condition

28.1%

16 of 57 rated 7-9

Fair condition

64.9%

37 of 57 rated 5-6

Poor condition

4 of 57 rated 4 or below

In-state Poor-share rank

#35 of 56

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

Condition distribution

Share of 57 NBI-tracked bridges by lowest applicable component rating.

Good

28.1% (16)

Fair

64.9% (37)

Poor

7% (4)

Roosevelt County's Poor-condition bridges carry 4,604 vehicle crossings a day

That is 10.3% of the county's reported daily bridge traffic on 7% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 1,151 crossings a day against 375 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 57 of 57 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

38.6% of Roosevelt County's bridges have passed the 50-year mark

22 of the 57 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 28.1% 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 51.2% of the county's Poor-condition bridge traffic

IRR - US 2 over CHELSEA CREEK, built 1960, carries 2,359 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 4,604 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1930s

3
1940s

1
1950s

11
1960s

4
1970s

6
1980s

5
1990s

8
2000s

7
2010s

6
2020s

6

What this shows Construction peaked in the 1950s, when 11 of the county's bridges still in the inventory were built, which is 19.3% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year is 1984, 7 years newer than the Montana average of 1977.

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

The 5 Montana counties nearest Roosevelt County in number of bridges, with their condition splits. Its 7% Poor share is the 4th-lowest of these 6. Its average build year of 1984 against a peer-group mean of 1977 is 7 years newer.

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

Bridge inventory size and condition shares for Roosevelt County and the 5 Montana counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Deer Lodge County	68	27.9%	66.2%	5.9%	1973
Silver Bow County	68	16.2%	82.4%	1.5%	1974
Sheridan County	66	16.7%	80.3%	3%	1979
Roosevelt County (this page)	57	28.1%	64.9%	7%	1984
Meagher County	53	20.8%	69.8%	9.4%	1980
Judith Basin County	48	56.3%	31.3%	12.5%	1979

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

Similar inventory size

Nearest county inventories outside MT (57 bridges here).

Summit County, CO · 57 bridges
DeSoto County, FL · 57 bridges
Dodge County, GA · 57 bridges
McIntosh County, GA · 57 bridges

Similar average build year

Nearest mean year-built outside MT (1984 here).

Hennepin County, MN · avg 1984 · 936 bridges
Duval County, FL · avg 1984 · 831 bridges
El Paso County, CO · avg 1984 · 686 bridges
Bell County, TX · avg 1984 · 660 bridges

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

All 57 Good 16 Fair 37 Poor 4

All bridges (57)

Sort:

Roosevelt County Bridge Snapshot

Condition distribution

Roosevelt County's Poor-condition bridges carry 4,604 vehicle crossings a day

38.6% of Roosevelt County's bridges have passed the 50-year mark

One structure carries 51.2% of the county's Poor-condition bridge traffic

How Roosevelt 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 (57)

COUNTY ROAD 1010

IRR - S 344

IRR - US 2

IRR - US 2

US 2

IRRCOUNTY ROAD 221

IRRCOUNTY ROAD 380

IRR - S 13

POPLAR RIVER RD

IRR - S 13

IRR - S 13

IRR - S 344

IRR - S 344

IRR COUNTY ROAD 20

S BAINVILLE RD

IRR - S 13

IRR - S 251

IRR - US 2

IRR - S 251

IRRCOUNTY ROAD 208

US 2

US-2

US 2

IRR - S 13

S 16

IRR - US 2

IRR - US 2

IRR - S 13

IRR - S 13

IRR - S 13

SLAB RD

IRR BIA RTE 7

IRR - S 13

IRR - US 2

IRR - US 2

S 16

IRR - S 13

RD 2051

IRR - S 251

S 16

IRR BIA RTE 34

S 327

COUNTY ROAD 249

THREE CORNERS RD

IRR - S 13

NEW ALIGNMENT BUIL

US 2

IRR BIA RTE 40

S 327

S 327

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