Total bridges
248
Public highway bridges in Klamath County
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.
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.
When Klamath County's bridges were built
248 bridges with a recorded construction year, grouped by decade
- 1900s 1
1900–1909
1 bridges
- 1920s 1
1920–1929
1 bridges
- 1930s 3
1930–1939
3 bridges
- 1940s 3
1940–1949
3 bridges
- 1950s 20
1950–1959
20 bridges
- 1960s
1960–1969
46 bridges
- 1970s
1970–1979
61 bridges
- 1980s
1980–1989
49 bridges
- 1990s 19
1990–1999
19 bridges
- 2000s
2000–2009
31 bridges
- 2010s 11
2010–2019
11 bridges
- 2020s 3
2020–2029
3 bridges
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.
| 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.
Poor-condition bridges (13)
ROAD
PoorOver: WILLIAMSON RIVER
(ORIG.# 9730000 - 0.7), Klamath, OR
Built 1969 Load: 2.7 t ADT: 23
FLOATING POINT RD
PoorOver: LITTLE DESCHUTES RIVER
1.5 MI N OF OR 58, Klamath, OR
Built 1980 Load: 3.9 t ADT: 73
IVORY PINE ROAD
PoorOver: MERYL CREEK
056 MI N HWY 140, Klamath, OR
Built 1970 Load: 9.4 t ADT: 434
E LANGELL VLY RD
PoorOver: LOST RIVER
001 MI W KELLER RD, Klamath, OR
Built 1967 Load: 14.6 t ADT: 398
HWY 429
PoorOver: CRESCENT CREEK
023 MI S HWY 18 JCT, Klamath, OR
Built 1954 Load: 21.7 t ADT: 147
SADDLE MT PIT RD
PoorOver: SPRAGUE RIVER
003 MI W OF SPRAGUE R RD, Klamath, OR
Built 1965 Load: 22.0 t ADT: 45
ODELL LK ACCESS RD
PoorOver: TRAPPER CREEK
W END ODELL LAKE, Klamath, OR
Built 1982 Load: 24.5 t ADT: 130
ROAD
PoorOver: SOUTH FORK SPRAGUE RIVER
NO DATA ENTERED, Klamath, OR
Built 1961 Load: 29.1 t ADT: 50
ROAD
PoorOver: BROWN CREEK
NO DATA ENTERED, Klamath, OR
Built 1967 Load: 34.5 t ADT: 20
ROAD
PoorOver: JACK CREEK
(ORIG.# 2653 - 9.6), Klamath, OR
Built 1959 Load: 36.3 t ADT: 6
ROAD
PoorOver: LONG BRANCH CREEK
NO DATA ENTERED, Klamath, OR
Built 1958 Load: 39.0 t ADT: 50
WU ROAD
PoorOver: DRAIN DITCH
004 MI E OF BLISS ROAD, Klamath, OR
Built 1974 Load: 67.1 t ADT: 68
E LANGELL VLY RD
PoorOver: DRAIN DITCH
008 MI W OF GERBER RD, Klamath, OR
Built 1976 Load: 74.4 t ADT: 446
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.