Total bridges
35
Public highway bridges in Gilliam County
County profile · official public datasets
Gilliam County, OR
35 public highway bridges tracked in the FHWA National Bridge Inventory: 51.4% rated Good, 48.6% Fair, 0% Poor.
- 35
- Public bridges
- 51.4%
- Good condition
- 0%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Gilliam County posts a top-10% lowest Poor-condition share among rated counties in the state across rated county bridge inventory.
- Top 8%
- lowest Poor share in state
- 0%
- Poor-condition share
- 35
- public highway bridges
- 1973
- 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.
Gilliam County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Gilliam County ranks #3 of 36 Oregon counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 0%). Gilliam County, Oregon contains 35 public highway bridges. Roughly 51.4% are rated “Good,” 48.6% “Fair,” and 0% “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
51.4%
18 of 35 rated 7-9
Fair condition
48.6%
17 of 35 rated 5-6
Poor condition
0%
0 of 35 rated 4 or below
In-state Poor-share rank
#3 of 36
Among Oregon counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 35 NBI-tracked bridges by lowest applicable component rating.
Good 51.4% (18)
Fair 48.6% (17)
Poor 0% (0)
71.4% of Gilliam County's bridges have passed the 50-year mark
25 of the 35 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 51.4% 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.
When Gilliam County's bridges were built
35 bridges with a recorded construction year, grouped by decade
- 1930s 1
1930–1939
1 bridges
- 1950s 5
1950–1959
5 bridges
- 1960s
1960–1969
13 bridges
- 1970s
1970–1979
7 bridges
- 1980s 3
1980–1989
3 bridges
- 1990s 2
1990–1999
2 bridges
- 2000s 1
2000–2009
1 bridges
- 2010s 1
2010–2019
1 bridges
- 2020s 2
2020–2029
2 bridges
What this shows Construction peaked in the 1960s, when 13 of the county's bridges still in the inventory were built, which is 37.1% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1973) matches the Oregon average (1975).
How Gilliam County compares with Oregon's closest counties by inventory size
The 5 Oregon counties nearest Gilliam County in number of bridges, with their condition splits. Its 0% Poor share is the 3rd-lowest of these 6. Its average build year of 1973 against a peer-group mean of 1974 is in line with the group.
Showing the 5 closest of 35 Oregon counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Jefferson County | 80 | 46.3% | 46.3% | 7.5% | 1980 |
| Crook County | 79 | 46.8% | 53.2% | 0% | 1980 |
| Morrow County | 70 | 45.7% | 51.4% | 2.9% | 1975 |
| Sherman County | 48 | 33.3% | 66.7% | 0% | 1963 |
| Gilliam County (this page) | 35 | 51.4% | 48.6% | 0% | 1973 |
| Wheeler County | 32 | 43.8% | 56.3% | 0% | 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 Gilliam 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 Gilliam County, both outside Oregon so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside OR (35 bridges here).
- Seminole County, GA · 35 bridges
- Manistee County, MI · 35 bridges
- Toole County, MT · 35 bridges
- Ransom County, ND · 35 bridges
Similar average build year
Nearest mean year-built outside OR (1973 here).
- Jefferson County, AL · avg 1973 · 1,068 bridges
- Erie County, NY · avg 1973 · 906 bridges
- Davidson County, TN · avg 1973 · 832 bridges
- Lancaster County, PA · avg 1973 · 801 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (17)
BARNETT RD
FairOver: ROCK CREEK
9.2 MI NW OF HWY 19, Gilliam, OR
Built 1957 Load: 7.5 t ADT: 93
I-84 (HWY 002)
FairOver: ARLINGTON VIADUCT
009 MI W ARLINGTON, Gilliam, OR
Built 1964 Load: 13.0 t ADT: 11,672
I-84 (HWY 002) WB
FairOver: WILLOW CREEK WEST
011 MI E HEPPNER JCT, Gilliam, OR
Built 1954 Load: 14.9 t ADT: 5,757
OR 206 (HWY 300)
FairOver: ROCK CREEK
103 MI E CONDON, Gilliam, OR
Built 1934 Load: 20.4 t ADT: 52
I-84 (HWY 002)
FairOver: BLALOCK CANYON RD
149 MI E SHERMAN GILL CLN, Gilliam, OR
Built 1964 Load: 21.4 t ADT: 11,995
TRAIL FORK ROAD
FairOver: THIRTYMILE CREEK
2.5 MI E OF HWY 19, Gilliam, OR
Built 1957 Load: 25.4 t ADT: 36
UPPER ROCK CR ROAD
FairOver: ROCK CREEK
2.9 MI SE OF HWY 19, Gilliam, OR
Built 1962 Load: 29.0 t ADT: 58
M. ROCK CREEK LN.
FairOver: ROCK CREEK
0.9 MI NW OF HWY 19, Gilliam, OR
Built 1960 Load: 29.5 t ADT: 57
WOLF HOLLOW LANE
FairOver: ROCK CREEK
4.4 MI NE OF HWY 19, Gilliam, OR
Built 1967 Load: 30.8 t ADT: 57
OR 74 (HWY 052)
FairOver: UPRR
027 MI N RHEA, Gilliam, OR
Built 1964 Load: 31.1 t ADT: 185
LONE ROCK ROAD
FairOver: LONE ROCK CREEK
LONE ROCK, Gilliam, OR
Built 2020 Load: 32.7 t ADT: 33
ALVILLE LANE
FairOver: FERRY CANYON CREEK
1.0 MI W OFF HWY 206, Gilliam, OR
Built 2013 Load: 34.7 t ADT: 13
FOURMILE ROAD
FairOver: EIGHTMILE CREEK
4.4 MI SE OF HWY 19, Gilliam, OR
Built 1958 Load: 37.2 t ADT: 15
MIKKALO LANE
FairOver: HAY CREEK
7.3 MI W OF HWY 19, Gilliam, OR
Built 1964 Load: 37.2 t ADT: 13
MORRIS ROAD
FairOver: ROCK CREEK
14.3 MI NW OF HWY 19, Gilliam, OR
Built 1991 Load: 38.1 t ADT: 20
MIKKALO LANE
FairOver: SCOTT CANYON CREEK
4.5 MI W OF HWY 19, Gilliam, OR
Built 1973 Load: 41.7 t ADT: 13
Middle Rock CRK LN
FairOver: JUNIPER CANYON CREEK
0.05 MI N OF HWY 19, Gilliam, OR
Built 1973 Load: 43.5 t ADT: 58
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.