Total bridges
48
Public highway bridges in Owyhee County
County profile · official public datasets
Owyhee County, ID
48 public highway bridges tracked in the FHWA National Bridge Inventory: 31.3% rated Good, 60.4% Fair, 8.3% Poor.
- 48
- Public bridges
- 31.3%
- Good condition
- 8.3%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Owyhee County posts a higher-than-median Poor-condition share among rated counties in the state across rated county bridge inventory.
- 34th
- of 44 on Poor share
- 8.3%
- Poor-condition share
- 48
- public highway bridges
- 1975
- 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.
Owyhee County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Owyhee County ranks #34 of 44 Idaho counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 8.3%). Owyhee County, Idaho contains 48 public highway bridges. Roughly 31.3% are rated “Good,” 60.4% “Fair,” and 8.3% “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
31.3%
15 of 48 rated 7-9
Fair condition
60.4%
29 of 48 rated 5-6
Poor condition
8.3%
4 of 48 rated 4 or below
In-state Poor-share rank
#34 of 44
Among Idaho counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 48 NBI-tracked bridges by lowest applicable component rating.
Good 31.3% (15)
Fair 60.4% (29)
Poor 8.3% (4)
Owyhee County's Poor-condition bridges carry 230 vehicle crossings a day
That is 0.5% of the county's reported daily bridge traffic on 8.3% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 58 crossings a day against 510 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 48 of 48 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
50% of Owyhee County's bridges have passed the 50-year mark
24 of the 48 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 31.3% 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 39.1% of the county's Poor-condition bridge traffic
SAGE ROAD over SUCCOR CREEK, built 1930, carries 90 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 230 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Owyhee County's bridges were built
48 bridges with a recorded construction year, grouped by decade
- 1920s 1
1920–1929
1 bridges
- 1930s
1930–1939
5 bridges
- 1950s
1950–1959
8 bridges
- 1960s
1960–1969
6 bridges
- 1970s
1970–1979
6 bridges
- 1980s
1980–1989
10 bridges
- 1990s 3
1990–1999
3 bridges
- 2000s 1
2000–2009
1 bridges
- 2010s
2010–2019
6 bridges
- 2020s 2
2020–2029
2 bridges
What this shows Construction peaked in the 1980s, when 10 of the county's bridges still in the inventory were built, which is 20.8% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1975) matches the Idaho average (1979).
How Owyhee County compares with Idaho's closest counties by inventory size
The 5 Idaho counties nearest Owyhee County in number of bridges, with their condition splits. Its 8.3% Poor share is the 4th-lowest of these 6. Its average build year of 1975 against a peer-group mean of 1978 is in line with the group.
Showing the 5 closest of 43 Idaho counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Gem County | 57 | 28.1% | 70.2% | 1.8% | 1976 |
| Lincoln County | 53 | 18.9% | 58.5% | 22.6% | 1973 |
| Owyhee County (this page) | 48 | 31.3% | 60.4% | 8.3% | 1975 |
| Benewah County | 47 | 21.3% | 74.5% | 4.3% | 1978 |
| Caribou County | 45 | 26.7% | 66.7% | 6.7% | 1985 |
| Clark County | 40 | 22.5% | 65% | 12.5% | 1977 |
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 Owyhee 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 Owyhee County, both outside Idaho so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside ID (48 bridges here).
- Wakulla County, FL · 48 bridges
- Evans County, GA · 48 bridges
- Carter County, MO · 48 bridges
- Judith Basin County, MT · 48 bridges
Similar average build year
Nearest mean year-built outside ID (1975 here).
- San Bernardino County, CA · avg 1975 · 1,422 bridges
- Lane County, OR · avg 1975 · 1,010 bridges
- Fulton County, GA · avg 1975 · 775 bridges
- Westmoreland County, PA · avg 1975 · 620 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Poor-condition bridges (4)
RIVER ROAD
PoorOver: VINSON WASH
2.0 N. 2.6 W. GRAND VIEW, Owyhee, ID
Built 1930 Load: 0.9 t ADT: 60
SALMON CREEK RD
PoorOver: REYNOLDS CREEK
1.6 N 9.8 W MURPHY, Owyhee, ID
Built 1960 Load: 5.4 t ADT: 20
SAGE ROAD
PoorOver: SUCCOR CREEK
1.0 S. 3.8 W. HOMEDALE, Owyhee, ID
Built 1930 Load: 10.0 t ADT: 90
SHEEP CAMP RD
PoorOver: GRANDVIEW IRRIGATION CNL
1.3 E. GRANDVIEW, Owyhee, ID
Built 1991 Load: 18.1 t ADT: 60
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.