Total bridges
66
Public highway bridges in Inyo County
County profile · official public datasets
Inyo County, CA
66 public highway bridges tracked in the FHWA National Bridge Inventory: 63.6% rated Good, 31.8% Fair, 4.5% Poor.
- 66
- Public bridges
- 63.6%
- Good condition
- 4.5%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Inyo County posts a better-than-median Poor-condition share among rated counties in the state across rated county bridge inventory.
- Top 26%
- lowest Poor share in state
- 4.5%
- Poor-condition share
- 66
- public highway bridges
- 1972
- 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.
Inyo County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Inyo County ranks #15 of 58 California counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 4.5%). Inyo County, California contains 66 public highway bridges. Roughly 63.6% are rated “Good,” 31.8% “Fair,” and 4.5% “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.
Good condition
63.6%
42 of 66 rated 7-9
Fair condition
31.8%
21 of 66 rated 5-6
Poor condition
4.5%
3 of 66 rated 4 or below
In-state Poor-share rank
#15 of 58
Among California counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 66 NBI-tracked bridges by lowest applicable component rating.
Good 63.6% (42)
Fair 31.8% (21)
Poor 4.5% (3)
Inyo County's Poor-condition bridges carry 4,650 vehicle crossings a day
That is 2% of the county's reported daily bridge traffic on 4.5% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,550 crossings a day against 3,759 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 66 of 66 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
36.4% of Inyo County's bridges have passed the 50-year mark
24 of the 66 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 63.6% 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 97.8% of the county's Poor-condition bridge traffic
U.S. HIGHWAY 6 over OWENS RIVER, built 1949, carries 4,550 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 3-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 4,650 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Inyo County's bridges were built
66 bridges with a recorded construction year, grouped by decade
- 1910s 3
1910–1919
3 bridges
- 1920s
1920–1929
8 bridges
- 1930s 1
1930–1939
1 bridges
- 1940s 5
1940–1949
5 bridges
- 1950s 1
1950–1959
1 bridges
- 1960s 1
1960–1969
1 bridges
- 1970s
1970–1979
10 bridges
- 1980s
1980–1989
20 bridges
- 1990s
1990–1999
9 bridges
- 2000s 5
2000–2009
5 bridges
- 2010s 3
2010–2019
3 bridges
What this shows Construction peaked in the 1980s, when 20 of the county's bridges still in the inventory were built, which is 30.3% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1972) matches the California average (1970).
How Inyo County compares with California's closest counties by inventory size
The 5 California counties nearest Inyo County in number of bridges, with their condition splits. Its 4.5% Poor share is the 2nd-lowest of these 6. Its average build year of 1972 against a peer-group mean of 1970 is in line with the group.
Showing the 5 closest of 57 California counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Modoc County | 87 | 49.4% | 49.4% | 1.1% | 1969 |
| San Benito County | 76 | 46.1% | 43.4% | 10.5% | 1971 |
| Inyo County (this page) | 66 | 63.6% | 31.8% | 4.5% | 1972 |
| Sierra County | 65 | 40% | 52.3% | 7.7% | 1972 |
| Amador County | 61 | 37.7% | 37.7% | 24.6% | 1966 |
| Mono County | 49 | 63.3% | 24.5% | 12.2% | 1970 |
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 Inyo 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 Inyo County, both outside California so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside CA (66 bridges here).
- Chugach County, AK · 66 bridges
- Broomfield County, CO · 66 bridges
- Cook County, GA · 66 bridges
- Greene County, GA · 66 bridges
Similar average build year
Nearest mean year-built outside CA (1972 here).
- Madison County, AL · avg 1972 · 710 bridges
- York County, PA · avg 1972 · 569 bridges
- Middlesex County, NJ · avg 1972 · 563 bridges
- Saunders County, NE · avg 1972 · 506 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (21)
CARROLL CRK RD
FairOver: LOS ANGELES AQUEDUCT
0.4 MI W OF RTE 395 JCT, Inyo, CA
Built 1927 Load: 16.8 t ADT: 50
WALKER CREEK RD
FairOver: LOS ANGELES AQUEDUCT
0.5 MI W OF RTE 395 JCT, Inyo, CA
Built 1927 Load: 16.8 t ADT: 50
OLD SHERWIN GRADE
FairOver: PINE CREEK
.04 MI S OF BIRCHIM LANE, Inyo, CA
Built 1919 Load: 17.2 t ADT: 520
COTTONWOOD POW RD
FairOver: LOS ANGELES AQUEDUCT
0.6 MI W OF RTE 395 JCT, Inyo, CA
Built 1927 Load: 18.1 t ADT: 50
COTTONWOOD RD
FairOver: LOS ANGELES AQUEDUCT
0.5 MI W OF RTE 395 JCT, Inyo, CA
Built 1927 Load: 18.1 t ADT: 50
ASH CREEK RD
FairOver: LOS ANGELES AQUEDUCT
0.8 MI W OF RTE 395 JCT, Inyo, CA
Built 1927 Load: 18.1 t ADT: 50
FALL RD
FairOver: LOS ANGELES AQUEDUCT
0.9 MI W OF RTE 395 JCT, Inyo, CA
Built 1927 Load: 18.1 t ADT: 50
GLACIER LODGE RD
FairOver: BIG PINE CREEK
3.8 MI W OF ROUTE 395, Inyo, CA
Built 1987 Load: 25.3 t ADT: 510
U.S. HIGHWAY 6
FairOver: LOWER MCNALLY CANAL
09-INY-006-6.46-BIS, Inyo, CA
Built 1949 Load: 26.2 t ADT: 4,550
MAZOURKA CYN RD
FairOver: LOS ANGELES AQUEDUCT
1.8 MI E OF RTE 395 JCT, Inyo, CA
Built 1919 Load: 26.2 t ADT: 204
STATE ROUTE 168
FairOver: OWENS RIVER
09-INY-168-R19.79, Inyo, CA
Built 1974 Load: 29.2 t ADT: 8,820
STATE ROUTE 168
FairOver: NORTH FORK BISHOP CREEK
09-INY-168-15.40-BIS, Inyo, CA
Built 1982 Load: 30.1 t ADT: 8,000
U.S. HIGHWAY 395
FairOver: NORTH FORK BISHOP CREEK
09-INY-395-117.61-BIS, Inyo, CA
Built 1971 Load: 32.4 t ADT: 21,550
US HIGHWAY 395 SB
FairOver: COTTONWOOD CREEK
09-INY-395-44.00, Inyo, CA
Built 2000 Load: 32.4 t ADT: 6,400
US HIGHWAY 395 NB
FairOver: COTTONWOOD CREEK
09-INY-395-44.00, Inyo, CA
Built 2000 Load: 32.4 t ADT: 6,400
LUBKEN CANYON ROAD
FairOver: LOS ANGELES AQUEDUCT
0.1 MI W OF ROUTE 395, Inyo, CA
Built 1991 Load: 32.4 t ADT: 100
PINE CREEK ROAD
FairOver: PINE CREEK
9.5 MI W OF RTE 395 JCT, Inyo, CA
Built 1984 Load: 32.4 t ADT: 200
N ROUND VALLEY RD
FairOver: PINE CREEK
0.1 MI N PINE CREEK RD, Inyo, CA
Built 1987 Load: 32.4 t ADT: 350
MANZANAR-REWARD RD
FairOver: LOS ANGELES AQUEDUCT
0.6 MI E/O RTE 395, Inyo, CA
Built 1996 Load: 32.4 t ADT: 100
MOFFAT RANCH RD
FairOver: LOS ANGELES AQUEDUCT
0.3 KM W. OF RTE 395, Inyo, CA
Built 1996 Load: 32.4 t ADT: 150
STATE ROUTE 168
FairOver: SOUTH FORK BISHOP CREEK
09-INY-168-15.79-BIS, Inyo, CA
Built 1982 Load: 36.9 t ADT: 8,000
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.