County profile · official public datasets

Clackamas County, OR

367 public highway bridges tracked in the FHWA National Bridge Inventory: 31.1% rated Good, 66.5% Fair, 2.5% Poor.

367
Public bridges
31.1%
Good condition
2.5%
Poor condition

The verdict

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

Clackamas County posts a better-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

Top 28%
lowest Poor share in state
2.5%
Poor-condition share
367
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.

Clackamas County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Clackamas County ranks #10 of 36 Oregon counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 2.5%). Clackamas County, Oregon contains 367 public highway bridges. Roughly 31.1% are rated “Good,” 66.5% “Fair,” and 2.5% “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.

Total bridges

367

Public highway bridges in Clackamas County

Good condition

31.1%

114 of 367 rated 7-9

Fair condition

66.5%

244 of 367 rated 5-6

Poor condition

2.5%

9 of 367 rated 4 or below

In-state Poor-share rank

#10 of 36

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

Condition distribution

Share of 367 NBI-tracked bridges by lowest applicable component rating.

Good
31.1% (114)
Fair
66.5% (244)
Poor
2.5% (9)

Clackamas County's Poor-condition bridges carry 35,357 vehicle crossings a day

That is 0.7% of the county's reported daily bridge traffic on 2.5% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 3,929 crossings a day against 6,104 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 367 of 367 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

61.9% of Clackamas County's bridges have passed the 50-year mark

227 of the 367 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 31.1% 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 50.7% of the county's Poor-condition bridge traffic

OR 99E (Hwy 81) over Partial Viaduct, built 1940, carries 17,911 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 9-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 35,357 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Clackamas County's bridges were built

367 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1970s, when 77 of the county's bridges still in the inventory were built, which is 21% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1975) matches the Oregon average (1975).

Source FHWA National Bridge Inventory (year built) As of 2024 NBI release

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

The 5 Oregon counties nearest Clackamas County in number of bridges, with their condition splits. Its 2.5% Poor share is the 2nd-lowest of these 6. Its average build year of 1975 against a peer-group mean of 1974 is in line with the group.

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

Bridge inventory size and condition shares for Clackamas County and the 5 Oregon counties closest to it in inventory size
County Bridges Poor
Multnomah County 473 3%
Jackson County 401 1.5%
Marion County 373 4.3%
Clackamas County (this page) 367 2.5%
Washington County 326 2.5%
Umatilla County 321 4%

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

Similar inventory size

Nearest county inventories outside OR (367 bridges here).

Similar average build year

Nearest mean year-built outside OR (1975 here).

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

All 367 Good 114 Fair 244 Poor 9

Good-condition bridges (114)

Hwy 064

Good

Over: Willamette River

0.7 MI N OREGON CITY CC, Clackamas, OR

Built 1970 Load: 9.1 t ADT: 86,557

OR 224 (HWY 171)

Good

Over: ROCK CREEK

3.2 M E OF HWY 64, Clackamas, OR

Built 1985 Load: 16.8 t ADT: 19,125

Strawberry Lane

Good

Over: Hwy 064

2.8 MI N OF OREGON CITY, Clackamas, OR

Built 1962 Load: 17.2 t ADT: 113,512

OR 224 (HWY 171)

Good

Over: MT SCOTT CREEK

0.07 MI W OF SE RUSK RD, Clackamas, OR

Built 1969 Load: 17.5 t ADT: 27,442

NO DATA ENTERED

Good

Over: SANDY RIVER

NO DATA ENTERED, Clackamas, OR

Built 2011 Load: 17.8 t ADT: 50

ELLWOOD AVE

Good

Over: LITTLE CLEAR CREEK

02.0 MI SE OF HWY 211, Clackamas, OR

Built 1976 Load: 18.1 t ADT: 58

NO DATA ENTERED

Good

Over: SAM CREEK

SEC 5 T6S R7E, Clackamas, OR

Built 2008 Load: 20.1 t ADT: 50

TEN EYCK RD

Good

Over: SANDY RIVER

2 MI NW HWY 26, Clackamas, OR

Built 2008 Load: 20.7 t ADT: 3,399

MILLPORT SLOUGH RD

Good

Over: JOHNSON CR

0020 MI E SE 17TH AVE, Clackamas, OR

Built 1963 Load: 21.1 t ADT: 252

Kleinsmith Road

Good

Over: BEAR CREEK

0.3 MI E OF Wildcat Mt RD, Clackamas, OR

Built 2009 Load: 21.1 t ADT: 174

ROAD

Good

Over: LOST CREEK

S-19 T-2S R-8E WM, Clackamas, OR

Built 1974 Load: 21.8 t ADT: 30

Wilsonville Road

Good

Over: SEELEY DITCH

0.52 mi W of HWY 001, Clackamas, OR

Built 2006 Load: 22.0 t ADT: 3,373

BONNEY RD. (3)

Good

Over: MILL CREEK

01.1 MI S OF HWY 211, Clackamas, OR

Built 1976 Load: 22.2 t ADT: 116

ROAD

Good

Over: SHELLROCK CREEK

S-02 T-6S R-7E WM, Clackamas, OR

Built 1954 Load: 22.7 t ADT: 50

HWY 171 (OR 224)

Good

Over: N/A

MP 30.70, Clackamas, OR

Built 1996 Load: 23.0 t ADT: 496

ROAD

Good

Over: STILL CREEK

S-33 T-3S R-8E WM, Clackamas, OR

Built 1967 Load: 23.6 t ADT: 45

ROAD

Good

Over: COLLAWASH RIVER

S-03 T-7S R-6E WM, Clackamas, OR

Built 1954 Load: 24.5 t ADT: 100

ROAD

Good

Over: BOYER CREEK

S-23 T-4S R-5E WM, Clackamas, OR

Built 1968 Load: 24.5 t ADT: 50

ROAD

Good

Over: STILL CREEK

S-30 T-3S R-8E WM, Clackamas, OR

Built 1965 Load: 24.5 t ADT: 45

ROAD

Good

Over: STILL CREEK

S-34 T-3S R-8E WM, Clackamas, OR

Built 1967 Load: 24.9 t ADT: 45

RUSK ROAD (N)

Good

Over: MT SCOTT CREEK

BTWN LAKE RD&HWY 212, Clackamas, OR

Built 1937 Load: 24.9 t ADT: 1,442

07 S 04 E 29.01:

Good

Over: SOUTH FORK MOLALLA RIVER

7.2 miles SE of Molalla o, Clackamas, OR

Built 1980 Load: 25.6 t ADT: 25

ROAD

Good

Over: STILL CREEK

S-33 T-3S R-8E WM, Clackamas, OR

Built 1961 Load: 26.1 t ADT: 45

Mattoon Road

Good

Over: Spring Creek

Mattoon Road, Clackamas, OR

Built 2009 Load: 26.2 t ADT: 136

ROAD

Good

Over: NORTH FORK CLACKAMAS RI*

S-24 T-4S R-5E WM, Clackamas, OR

Built 1969 Load: 26.3 t ADT: 50

ROAD

Good

Over: CLACKAMAS RIVER

S-13 T-7S R-7E WM, Clackamas, OR

Built 1957 Load: 27.2 t ADT: 50

CHILDS RD

Good

Over: OSWEGO CANAL

1.6 MI W OF STAFFORD RD, Clackamas, OR

Built 2000 Load: 27.5 t ADT: 9,500

ROAD

Good

Over: CAMP CREEK

S-19 T-3S R-8E WM, Clackamas, OR

Built 1967 Load: 28.1 t ADT: 25

US 26 (HWY 026)

Good

Over: BEAR CREEK

3.0 MI E RHODODENDRON PO, Clackamas, OR

Built 2005 Load: 28.2 t ADT: 8,961

07 S 04 E 01.01:

Good

Over: TRIB TO LOST CREEK

7.2 miles SE of Molalla o, Clackamas, OR

Built 1974 Load: 28.5 t ADT: 20

DHOOGE ROAD (N)

Good

Over: NATE CREEK

01.0 MI N OF HWY 211, Clackamas, OR

Built 1971 Load: 28.8 t ADT: 86

Hwy 161

Good

Over: Molalla River

2.7 MI NE OF MOLALLA, Clackamas, OR

Built 1996 Load: 28.8 t ADT: 5,631

422ND AVE

Good

Over: CEDAR CREEK

0.5 MILES S COALMAN RD., Clackamas, OR

Built 1996 Load: 29.5 t ADT: 695

LOLO PASS RD

Good

Over: Bear Creek

0.03 M N OF HWY 026, Clackamas, OR

Built 2006 Load: 29.9 t ADT: 2,325

ROAD

Good

Over: FARM CREEK

S-15 T-7S R-6E WM, Clackamas, OR

Built 1967 Load: 30.0 t ADT: 100

06 S 04 E 06.00:

Good

Over: NORTH FORK MOLALLA RIVER

5.7 miles NE of Dickey Pr, Clackamas, OR

Built 1968 Load: 30.5 t ADT: 100

SOUTH SHORE BLVD

Good

Over: OSWEGO CANAL

4 MI S LAKEVIEW BLVD, Clackamas, OR

Built 2005 Load: 30.5 t ADT: 9,102

STAFFORD RD

Good

Over: TUALATIN RIVER

1 MILE NW OF I-205, Clackamas, OR

Built 2010 Load: 30.5 t ADT: 9,836

FOSTER RD

Good

Over: ROCK CREEK

1.8 M N OF HWY 212, Clackamas, OR

Built 1976 Load: 30.8 t ADT: 11,400

ROAD

Good

Over: SALMON RIVER

S-27 T-3S R-7E WM, Clackamas, OR

Built 1958 Load: 30.9 t ADT: 50

ROAD

Good

Over: BLISTER CREEK

S-14 T-7S R-5E WM, Clackamas, OR

Built 1967 Load: 31.8 t ADT: 200

Hwy 026

Good

Over: Salmon River

UNKNOWN, Clackamas, OR

Built 2005 Load: 31.8 t ADT: 2,159

07 S 03 E 14.02:

Good

Over: COPPER CREEK

7.2 miles SE of Molalla o, Clackamas, OR

Built 1977 Load: 32.4 t ADT: 10

Road

Good

Over: SOUTH FORK CLACKAMAS AOP

OR-211 S CONTINUE FOR 4., Clackamas, OR

Built 2018 Load: 32.4 t ADT: 50

SUNNYBROOK ST (W)

Good

Over: UNKNOWN CREEK

SOUTH OF SUNNYSIDE ROAD, Clackamas, OR

Built 2001 Load: 32.7 t ADT: 12,215

GRAVES ROAD

Good

Over: MILK CREEK

0.7 MI E OF HWY 213, Clackamas, OR

Built 2005 Load: 32.7 t ADT: 520

GRAHAMS FERRY ROAD

Good

Over: CORRAL CREEK

00.5 MI N OF WILSONVILLE, Clackamas, OR

Built 1968 Load: 33.0 t ADT: 604

FERNWOOD RD

Good

Over: WOODCOCK CREEK

3.0MI E OF DICKEY PRAIRIE, Clackamas, OR

Built 1968 Load: 33.0 t ADT: 329

Arrowhead Crk Ln

Good

Over: DRAINAGE DITCH

.1 mi W of Industrial Way, Clackamas, OR

Built 2006 Load: 33.0 t ADT: 131

BEAVER CREEK RD

Good

Over: BUCKNER CREEK

6.22 MI NORTH OF HWY 161, Clackamas, OR

Built 2006 Load: 33.4 t ADT: 426

Read our methodology - how this data is sourced, computed, and verified.

Related

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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.