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.

Total bridges

Public highway bridges in Owyhee County

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.

1920s

1
1930s

5
1950s

8
1960s

6
1970s

6
1980s

10
1990s

3
2000s

1
2010s

6
2020s

2

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.

Bridge inventory size and condition shares for Owyhee County and the 5 Idaho counties closest to it in inventory size
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.

All 48 Good 15 Fair 29 Poor 4

All bridges (48)

Sort:

Owyhee County Bridge Snapshot

Condition distribution

Owyhee County's Poor-condition bridges carry 230 vehicle crossings a day

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

One structure carries 39.1% of the county's Poor-condition bridge traffic

How Owyhee County compares with Idaho'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 (48)

RIVER ROAD

DAVIS ROAD

S. EDISON ROAD

US 95

RIVER RUN ROAD

PERSHALL RD

BOULDER ROAD

US 95

3708: DEEP CREEK

BEET DUMP ROAD

SH 78

RIVER ROAD

3 CREEK ROAD

SHOOFLY CUTOFF

ROWLAND ROAD

SH 167

SH 51

SH 51

SH 78

SH 78

S3706;PLEASANT VLY

SH 45

SH 167

SH 55

SH 78

HOT SPRINGS ROAD

SH 78

US 95

SH 78

STC3702;CLOVER-3CR

ROWLAND ROAD

3708: DEEP CREEK

SH 51

FLINT CREEK ROAD

3708: DEEP CREEK

IRR BIA RTE 901

IRR BIA RTE 904

SH 78

SH 19

SH 51

FLINT CREEK ROAD

HOT SPRINGS ROAD

REYNOLDS CR RD

STC3710;SUMMER CMP

RIVER ROAD

SALMON CREEK RD

SAGE ROAD

SHEEP CAMP RD

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