County profile · official public datasets

Grant County, OR

144 public highway bridges tracked in the FHWA National Bridge Inventory: 45.1% rated Good, 49.3% Fair, 5.6% Poor.

144
Public bridges: 45.1%
Good condition: 5.6%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Grant County pairs a higher-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

26th
of 36 on Poor share: 5.6%
Poor-condition share: 144
public highway bridges: 1980
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.

Grant County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Grant County ranks #26 of 36 Oregon counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 5.6%). Grant County, Oregon contains 144 public highway bridges. Roughly 45.1% are rated “Good,” 49.3% “Fair,” and 5.6% “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

144

Public highway bridges in Grant County

Good condition

45.1%

65 of 144 rated 7-9

Fair condition

49.3%

71 of 144 rated 5-6

Poor condition

5.6%

8 of 144 rated 4 or below

In-state Poor-share rank

#26 of 36

Among Oregon counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 144 NBI-tracked bridges by lowest applicable component rating.

Good

45.1% (65)

Fair

49.3% (71)

Poor

5.6% (8)

Grant County's Poor-condition bridges carry 329 vehicle crossings a day

That is 0.7% of the county's reported daily bridge traffic on 5.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 41 crossings a day against 345 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 144 of 144 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

47.2% of Grant County's bridges have passed the 50-year mark

68 of the 144 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 45.1% 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 33.7% of the county's Poor-condition bridge traffic

NUGGET STREET over CANYON CREEK, built 1972, carries 111 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 8-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 329 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

pre-1900

1
1920s

1
1930s

4
1940s

4
1950s

13
1960s

34
1970s

24
1980s

10
1990s

17
2000s

24
2010s

10
2020s

2

What this shows Construction peaked in the 1960s, when 34 of the county's bridges still in the inventory were built, which is 23.6% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1980, 5 years newer than the Oregon average of 1975.

How Grant County compares with Oregon's closest counties by inventory size

The 5 Oregon counties nearest Grant County in number of bridges, with their condition splits. Its 5.6% Poor share is the 5th-lowest of these 6. Its average build year of 1980 against a peer-group mean of 1978 is in line with the group.

Showing the 5 closest of 35 Oregon counties eligible for comparison.

Bridge inventory size and condition shares for Grant County and the 5 Oregon counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Clatsop County	155	32.9%	63.2%	3.9%	1974
Deschutes County	152	56.6%	42.1%	1.3%	1986
Yamhill County	149	24.2%	71.1%	4.7%	1975
Wasco County	148	31.8%	60.1%	8.1%	1968
Grant County (this page)	144	45.1%	49.3%	5.6%	1980
Harney County	130	54.6%	43.1%	2.3%	1985

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 Grant 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 Grant County, both outside Oregon so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside OR (144 bridges here).

Muscatine County, IA · 144 bridges
Anderson County, KS · 144 bridges
Webster County, KY · 144 bridges
Muskegon County, MI · 144 bridges

Similar average build year

Nearest mean year-built outside OR (1980 here).

Tulsa County, OK · avg 1980 · 1,135 bridges
Miami-Dade County, FL · avg 1980 · 1,057 bridges
Pulaski County, AR · avg 1980 · 721 bridges
McLennan County, TX · avg 1980 · 714 bridges

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 144 Good 65 Fair 71 Poor 8

All bridges (144)

Sort:

Grant County Bridge Snapshot

Condition distribution

Grant County's Poor-condition bridges carry 329 vehicle crossings a day

47.2% of Grant County's bridges have passed the 50-year mark

One structure carries 33.7% of the county's Poor-condition bridge traffic

How Grant County compares with Oregon'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 (144)

3600000

CO RD 18

COUNTY RD 29

C45-MOON CREEK RD

COUNTY RD 15

INLAND ST

C70-WIDOWS CRK RD

COUNTY RD 44

7569: SKULL CANYON

US 26 (HWY 005)

COUNTY RD 1

C44-BELSHAW CRK RD

COUNTY RD

ROAD

US 26 (HWY 005)

OR 19 (HWY 005)

US 395 (HWY 028)

US 26 (HWY 005)

OR 19 (HWY 005)

USFS RD

US 395 (HWY 028)

C4-WALL CREEK RD

COUNTY RD 60

COUNTY RD 65

US 26 (HWY 005)

US 395 (HWY 028)

PORTAL LANE

US 395 (HWY 028)

OS 100 BRIDGE ST

ROAD

US 26 (HWY 005)

FS ROAD

HWY 48

US 395 (HWY 048)

2400000

2400000

HWY 28 FRONT. RD

INGLE ST

COUNTY RD 37

FAS B540

US 26 (HWY 005)

7569: NORTH FORK J

ROAD

US 395 (HWY 028)

COUNTY RD 42

COUNTY RD 42

3690000

US 26 (HWY 005)

US 395 (HWY 028)

US 26 (HWY 005)

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