County profile · official public datasets

Columbia County, WA

86 public highway bridges tracked in the FHWA National Bridge Inventory: 45.3% rated Good, 44.2% Fair, 10.5% Poor.

86
Public bridges: 45.3%
Good condition: 10.5%
Poor condition

The verdict

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

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

36th
of 39 on Poor share: 10.5%
Poor-condition share: 86
public highway bridges: 1979
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.

Columbia County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Columbia County ranks #36 of 39 Washington counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 10.5%). Columbia County, Washington contains 86 public highway bridges. Roughly 45.3% are rated “Good,” 44.2% “Fair,” and 10.5% “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 Columbia County

Good condition

45.3%

39 of 86 rated 7-9

Fair condition

44.2%

38 of 86 rated 5-6

Poor condition

10.5%

9 of 86 rated 4 or below

In-state Poor-share rank

#36 of 39

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

Condition distribution

Share of 86 NBI-tracked bridges by lowest applicable component rating.

Good

45.3% (39)

Fair

44.2% (38)

Poor

10.5% (9)

Columbia County's Poor-condition bridges carry 5,214 vehicle crossings a day

That is 15.9% of the county's reported daily bridge traffic on 10.5% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 579 crossings a day against 406 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 86 of 86 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

52.3% of Columbia County's bridges have passed the 50-year mark

45 of the 86 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 45.3% 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 46.6% of the county's Poor-condition bridge traffic

US 12 over WAREHOUSE YARD, built 1933, carries 2,430 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 9-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 5,214 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

2
1920s

2
1930s

2
1950s

2
1960s

25
1970s

16
1980s

4
1990s

14
2000s

13
2010s

5
2020s

1

What this shows Construction peaked in the 1960s, when 25 of the county's bridges still in the inventory were built, which is 29.1% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1979) matches the Washington average (1975).

How Columbia County compares with Washington's closest counties by inventory size

The 5 Washington counties nearest Columbia County in number of bridges, with their condition splits. Its 10.5% Poor share is the 4th-lowest of these 6. Its average build year of 1979 against a peer-group mean of 1980 is in line with the group.

Showing the 5 closest of 38 Washington counties eligible for comparison.

Bridge inventory size and condition shares for Columbia County and the 5 Washington counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Kitsap County	115	71.3%	27.8%	0.9%	1989
Jefferson County	99	57.6%	38.4%	4%	1982
Klickitat County	90	24.4%	67.8%	7.8%	1975
Columbia County (this page)	86	45.3%	44.2%	10.5%	1979
Stevens County	75	40%	48%	12%	1973
Pend Oreille County	71	54.9%	32.4%	12.7%	1981

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

Similar inventory size

Nearest county inventories outside WA (86 bridges here).

Catoosa County, GA · 86 bridges
Mason County, IL · 86 bridges
Starke County, IN · 86 bridges
Modoc County, CA · 87 bridges

Similar average build year

Nearest mean year-built outside WA (1979 here).

Pima County, AZ · avg 1979 · 1,150 bridges
Jefferson County, KY · avg 1979 · 662 bridges
Spartanburg County, SC · avg 1979 · 638 bridges
McPherson County, KS · avg 1979 · 586 bridges

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

All 86 Good 39 Fair 38 Poor 9

All bridges (86)

Sort:

Columbia County Bridge Snapshot

Condition distribution

Columbia County's Poor-condition bridges carry 5,214 vehicle crossings a day

52.3% of Columbia County's bridges have passed the 50-year mark

One structure carries 46.6% of the county's Poor-condition bridge traffic

How Columbia County compares with Washington'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 (86)

Harting Grade

ROBINSON FORK ROAD

Wolf Fork Road

ROAD

WELLER CANYON ROAD

WOLF FORK RD

6TH STREET

SR 261

US 12

WOLF FORK ROAD

POWERS ROAD

ROAD

SOUTH PATIT ROAD

TURNER ROAD

SMITH HOLLOW RD.

ROAD

USFS ROAD

Tucannon Road

ROAD

Thorn Hollow Road

US 12

FIRST STREET

ARCHER ROAD

Whiskey Creek Road

US 12

MEAD ROAD

SR 261

KING GRADE

BAILEYSBURG ROAD

SOUTH PATIT ROAD

ROSE GULCH ROAD

ROAD

TUCANNON ROAD

US 12

KELLOG HOLLOW RD.

US 12

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