County profile · official public datasets

Klamath County, OR

248 public highway bridges tracked in the FHWA National Bridge Inventory: 46% rated Good, 48.8% Fair, 5.2% Poor.

248
Public bridges: 46%
Good condition: 5.2%
Poor condition

The verdict

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

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

25th
of 36 on Poor share: 5.2%
Poor-condition share: 248
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.

Klamath County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Klamath County ranks #25 of 36 Oregon counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 5.2%). Klamath County, Oregon contains 248 public highway bridges. Roughly 46% are rated “Good,” 48.8% “Fair,” and 5.2% “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

248

Public highway bridges in Klamath County

Good condition

46%

114 of 248 rated 7-9

Fair condition

48.8%

121 of 248 rated 5-6

Poor condition

5.2%

13 of 248 rated 4 or below

In-state Poor-share rank

#25 of 36

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

Condition distribution

Share of 248 NBI-tracked bridges by lowest applicable component rating.

Good

46% (114)

Fair

48.8% (121)

Poor

5.2% (13)

Klamath County's Poor-condition bridges carry 1,890 vehicle crossings a day

That is 0.4% of the county's reported daily bridge traffic on 5.2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 145 crossings a day against 1,378 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 248 of 248 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

40.3% of Klamath County's bridges have passed the 50-year mark

100 of the 248 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 46% 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 23.6% of the county's Poor-condition bridge traffic

E LANGELL VLY RD over DRAIN DITCH, built 1976, carries 446 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 13-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 1,890 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

1
1920s

1
1930s

3
1940s

3
1950s

20
1960s

46
1970s

61
1980s

49
1990s

19
2000s

31
2010s

11
2020s

3

What this shows Construction peaked in the 1970s, when 61 of the county's bridges still in the inventory were built, which is 24.6% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1979) matches the Oregon average (1975).

How Klamath County compares with Oregon's closest counties by inventory size

The 5 Oregon counties nearest Klamath County in number of bridges, with their condition splits. Its 5.2% Poor share is the 4th-lowest of these 6. Its average build year of 1979 against a peer-group mean of 1975 is in line with the group.

Showing the 5 closest of 35 Oregon counties eligible for comparison.

Bridge inventory size and condition shares for Klamath County and the 5 Oregon counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Coos County	254	40.9%	55.9%	3.1%	1978
Klamath County (this page)	248	46%	48.8%	5.2%	1979
Josephine County	226	35%	62.4%	2.7%	1971
Tillamook County	225	35.6%	59.6%	4.9%	1978
Benton County	190	32.6%	60%	7.4%	1974
Lincoln County	190	41.6%	51.1%	7.4%	1974

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

Similar inventory size

Nearest county inventories outside OR (248 bridges here).

Crawford County, AR · 248 bridges
Cherokee County, IA · 248 bridges
Poweshiek County, IA · 248 bridges
Lowndes County, MS · 248 bridges

Similar average build year

Nearest mean year-built outside OR (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 248 Good 114 Fair 121 Poor 13

Fair-condition bridges (121)

Sort:

Klamath County Bridge Snapshot

Condition distribution

Klamath County's Poor-condition bridges carry 1,890 vehicle crossings a day

40.3% of Klamath County's bridges have passed the 50-year mark

One structure carries 23.6% of the county's Poor-condition bridge traffic

How Klamath County compares with Oregon'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 (121)

CHEYNE RD

OR 140 (HWY 020)

W LANGELL VLY RD

MILITARY CROSSING

OR 140 (HWY 020)

US 97 (HWY 004)

US 97 (HWY 004)

SEVENMILE ROAD

OR 140 (HWY 020)

ROYCE MT WAY

SUMMERS LANE

ROAD

ROAD

ROAD

OR 39 (HWY 050) SB

OR 39 (HWY 050)

ROAD

ROAD

WASHBURN WAY

BERGDORF ROAD

CRESCENT CUTOFF RD

CRESCENT CUTOFF RD

GALE ROAD

DEHLINGER LANE

SILVER LAKE ROAD

SILVER LAKE ROAD

DODDS HOLLOW

I O O F CEMETRY RD

REEDER RD

STATE LINE RD

SUTY ROAD

WILSON RD

MATNEY WAY

CAMPBELL RD

WASHBURN WAY

OLD MIDLAND ROAD

SOUTHSIDE BYPASS

OR 140 (HWY 020)

WASHINGTON ST

OR 140 (HWY 020)

OR 140 (HWY 020)

S SIDE BYPASS

HEMLOCK CR. RD.

CHILOQUIN RIDGE RD

ROAD

ROAD

ROAD

ROAD

WASHBURN WAY

OR 39 (HWY 050)

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