Total bridges
204
Public highway bridges in Flathead County
County profile · official public datasets
Flathead County, MT
204 public highway bridges tracked in the FHWA National Bridge Inventory: 30.9% rated Good, 64.2% Fair, 4.9% Poor.
- 204
- Public bridges
- 30.9%
- Good condition
- 4.9%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Flathead County pairs a better-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.
- Top 34%
- lowest Poor share in state
- 4.9%
- Poor-condition share
- 204
- public highway bridges
- 1983
- 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.
Flathead County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Flathead County ranks #19 of 56 Montana counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 4.9%). Flathead County, Montana contains 204 public highway bridges. Roughly 30.9% are rated “Good,” 64.2% “Fair,” and 4.9% “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.
Good condition
30.9%
63 of 204 rated 7-9
Fair condition
64.2%
131 of 204 rated 5-6
Poor condition
4.9%
10 of 204 rated 4 or below
In-state Poor-share rank
#19 of 56
Among Montana counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 204 NBI-tracked bridges by lowest applicable component rating.
Good 30.9% (63)
Fair 64.2% (131)
Poor 4.9% (10)
Flathead County's Poor-condition bridges carry 13,131 vehicle crossings a day
That is 2.9% of the county's reported daily bridge traffic on 4.9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,313 crossings a day against 2,597 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 204 of 204 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
32.8% of Flathead County's bridges have passed the 50-year mark
67 of the 204 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 30.9% 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 62.1% of the county's Poor-condition bridge traffic
S 82 over FLATHEAD RIVER, built 1955, carries 8,155 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 10-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 13,131 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Flathead County's bridges were built
204 bridges with a recorded construction year, grouped by decade
- 1910s 1
1910–1919
1 bridges
- 1920s 3
1920–1929
3 bridges
- 1930s 8
1930–1939
8 bridges
- 1950s 11
1950–1959
11 bridges
- 1960s
1960–1969
35 bridges
- 1970s
1970–1979
24 bridges
- 1980s
1980–1989
38 bridges
- 1990s
1990–1999
30 bridges
- 2000s
2000–2009
32 bridges
- 2010s
2010–2019
21 bridges
- 2020s 1
2020–2029
1 bridges
What this shows Construction peaked in the 1980s, when 38 of the county's bridges still in the inventory were built, which is 18.6% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1983, 6 years newer than the Montana average of 1977.
How Flathead County compares with Montana's closest counties by inventory size
The 5 Montana counties nearest Flathead County in number of bridges, with their condition splits. Its 4.9% Poor share is the 3rd-lowest of these 6. Its average build year of 1983 against a peer-group mean of 1975 is 8 years newer.
Showing the 5 closest of 55 Montana counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Gallatin County | 210 | 19% | 76.7% | 4.3% | 1977 |
| Missoula County | 206 | 33.5% | 58.7% | 7.8% | 1976 |
| Flathead County (this page) | 204 | 30.9% | 64.2% | 4.9% | 1983 |
| Lewis and Clark County | 200 | 58% | 36.5% | 5.5% | 1979 |
| Lincoln County | 190 | 38.4% | 46.8% | 14.7% | 1977 |
| Cascade County | 185 | 41.6% | 54.6% | 3.8% | 1965 |
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 Flathead 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 Flathead County, both outside Montana so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside MT (204 bridges here).
- Greene County, AL · 204 bridges
- Pembina County, ND · 204 bridges
- Okfuskee County, OK · 204 bridges
- Robertson County, TN · 204 bridges
Similar average build year
Nearest mean year-built outside MT (1983 here).
- Dallas County, TX · avg 1983 · 3,230 bridges
- Bexar County, TX · avg 1983 · 2,342 bridges
- Sedgwick County, KS · avg 1983 · 1,333 bridges
- Will County, IL · avg 1983 · 649 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
All bridges (204)
W RESERVE DR
PoorOver: WHITEFISH RIVER
2M N KALISPELL, Flathead, MT
Built 1983 Load: 29.9 t ADT: 100
IRR-US 2
PoorOver: UNSTABLE SLOPE
1.9M SE ESSEX, Flathead, MT
Built 1981 Load: 32.7 t ADT: 965
HOLT STAGE RD
PoorOver: FLATHEAD RIV OVERFL0 014
2M E KALISPELL, Flathead, MT
Built 1992 Load: 32.7 t ADT: 100
FOREST ROAD
PoorOver: GOOD CREEK
GREGG CREEK ROAD, Flathead, MT
Built 1962 Load: 34.3 t ADT: 20
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.