County profile · official public datasets

Houghton County, MI

58 public highway bridges tracked in the FHWA National Bridge Inventory: 63.8% rated Good, 32.8% Fair, 3.4% Poor.

58
Public bridges
63.8%
Good condition
3.4%
Poor condition

The verdict

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

Houghton County pairs a top-10% lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 10%
lowest Poor share in state
3.4%
Poor-condition share
58
public highway bridges
1984
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.

Houghton County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Houghton County ranks #8 of 83 Michigan counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 3.4%). Houghton County, Michigan contains 58 public highway bridges. Roughly 63.8% are rated “Good,” 32.8% “Fair,” and 3.4% “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

58

Public highway bridges in Houghton County

Good condition

63.8%

37 of 58 rated 7-9

Fair condition

32.8%

19 of 58 rated 5-6

Poor condition

3.4%

2 of 58 rated 4 or below

In-state Poor-share rank

#8 of 83

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

Condition distribution

Share of 58 NBI-tracked bridges by lowest applicable component rating.

Good
63.8% (37)
Fair
32.8% (19)
Poor
3.4% (2)

Houghton County's Poor-condition bridges carry 90 vehicle crossings a day

That is 0.1% of the county's reported daily bridge traffic on 3.4% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 45 crossings a day against 597 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 58 of 58 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

25.9% of Houghton County's bridges have passed the 50-year mark

15 of the 58 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 63.8% 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 88.9% of the county's Poor-condition bridge traffic

WOOD BUSH ROAD over TRAPROCK RIVER, built 1900, carries 80 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 2-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 90 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Houghton County's bridges were built

58 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1980s, when 15 of the county's bridges still in the inventory were built, which is 25.9% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1984, 8 years newer than the Michigan average of 1976.

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

How Houghton County compares with Michigan's closest counties by inventory size

The 5 Michigan counties nearest Houghton County in number of bridges, with their condition splits. Its 3.4% Poor share is the 1st-lowest of these 6. Its average build year of 1984 against a peer-group mean of 1970 is 14 years newer.

Showing the 5 closest of 82 Michigan counties eligible for comparison.

Bridge inventory size and condition shares for Houghton County and the 5 Michigan counties closest to it in inventory size
County Bridges Poor
Gladwin County 63 6.3%
Mackinac County 63 19%
Houghton County (this page) 58 3.4%
Crawford County 54 18.5%
Iron County 54 20.4%
Schoolcraft County 54 5.6%

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

Similar inventory size

Nearest county inventories outside MI (58 bridges here).

Similar average build year

Nearest mean year-built outside MI (1984 here).

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

All 58 Good 37 Fair 19 Poor 2

Good-condition bridges (37)

FOREST ROAD 2276

Good

Over: SILVER RIVER

6.5 MI S OF ALSTON, Houghton, MI

Built 1954 Load: 16.2 t ADT: 50

HOROSCOPE RD P127

Good

Over: N BR OTTER RIVER

2 MI W OF ELO, Houghton, MI

Built 1984 Load: 25.9 t ADT: 60

POYHONEN ROAD

Good

Over: MISERY RIVER

1.5 NW/M-26 NEAR WYANDOTT, Houghton, MI

Built 2004 Load: 27.9 t ADT: 5

S LAIRD RD L137

Good

Over: W BR STURGEON R

2 MI S OF ALSTON, Houghton, MI

Built 1983 Load: 29.2 t ADT: 48

COUNTY ROAD 161

Good

Over: EAST BR ONTONAGON RIVER

4.5 MI E 1.0 MI S KENTON, Houghton, MI

Built 1987 Load: 32.4 t ADT: 50

SUPERIOR RD P651

Good

Over: PILGRIM RIVER

2 MI S OF DODGEVILLE, Houghton, MI

Built 2020 Load: 32.4 t ADT: 2,410

COUNTY ROAD EM260

Good

Over: LAKE GERALD

.3 MI S .3 MI E TWIN LAKE, Houghton, MI

Built 1986 Load: 32.4 t ADT: 100

PIKE LAKE RD L657

Good

Over: W BR OTTER RIVER

2.3 MI N OF NISULA, Houghton, MI

Built 1979 Load: 34.6 t ADT: 100

COUNTY ROAD P106B

Good

Over: OTTER RIVER

1MI W 2.25 MI N TAPIOLA, Houghton, MI

Built 1985 Load: 35.6 t ADT: 50

STURGEON RIVER RD

Good

Over: BRANCH OF STURGEON RIVER

1 1/2MILES S OF CHASSEL, Houghton, MI

Built 1985 Load: 36.4 t ADT: 120

HAZEL RD L127

Good

Over: W BR STURGEON R

.5 MI S OF HAZEL, Houghton, MI

Built 1985 Load: 38.3 t ADT: 100

TOWNSHIP PARK ROAD

Good

Over: TRAPROCK RIVER

2 MI S 1 MI E COPPER CITY, Houghton, MI

Built 2007 Load: 39.4 t ADT: 100

LINCOLN SCHOOL RD.

Good

Over: TRAPROCK RIVER

1 MI S 1 MI E COPPER CITY, Houghton, MI

Built 2007 Load: 39.4 t ADT: 100

CO RD S10B(ANGMAN)

Good

Over: TRAPROCK RIVER

2.5 MI EAST OF LAURIUM, Houghton, MI

Built 2002 Load: 39.4 t ADT: 240

COUNTY ROAD S10

Good

Over: TRAPROCK RIVER

1 MI E 2.1 MI N LAKE LIND, Houghton, MI

Built 2000 Load: 39.4 t ADT: 240

COUNTY ROAD S10C

Good

Over: TRAPROCK RIVER

1 MI E 2 MI N LAKE LINDEN, Houghton, MI

Built 2002 Load: 39.4 t ADT: 240

COUNTY ROAD P106A

Good

Over: NORTH BR OTTER RIVER

1.25 MI W 1 MI N TAPIOLA, Houghton, MI

Built 1988 Load: 39.6 t ADT: 20

M-38

Good

Over: SILVER RIVER

0.7 MI W OF BARAGA COL, Houghton, MI

Built 2015 Load: 40.2 t ADT: 600

PARADISE RD

Good

Over: PILGRIM RIVER

PORTAGE TWP SEC 7, Houghton, MI

Built 2019 Load: 42.1 t ADT: 1,903

VALLEY RD S641

Good

Over: TRAP ROCK RIVER

4 MI N OF LAKE LINDEN, Houghton, MI

Built 1992 Load: 44.8 t ADT: 281

FORSMAN RD

Good

Over: GOOSENECK CREEK

0.7 MI E OF AIRPORT PK RD, Houghton, MI

Built 2019 Load: 45.4 t ADT: 86

COUNTY ROAD P108

Good

Over: N BRANCH OF OTTER RIV

2 MI W 1 MI S OF TAPIOLA, Houghton, MI

Built 1994 Load: 46.3 t ADT: 80

COUNTY ROAD 651G

Good

Over: N BRANCH OF OTTER RIVER

.25 MI W 4.25 MI N TAPIOL, Houghton, MI

Built 2002 Load: 49.3 t ADT: 50

HOROSCOPE RD L127

Good

Over: W BR OTTER RIVER

3 MI N OF HAZEL, Houghton, MI

Built 1984 Load: 49.9 t ADT: 60

SALO RD

Good

Over: LILY CREEK

0.38 MI S OF WAASA RD, Houghton, MI

Built 2018 Load: 52.8 t ADT: 296

M-26

Good

Over: QUINCY CREEK

4.1 MI SW OF LAKE LINDEN, Houghton, MI

Built 2021 Load: 58.0 t ADT: 5,200

CANAL RD

Good

Over: COLES CREEK

120 FT SE OF COLES CRK RD, Houghton, MI

Built 2018 Load: 58.0 t ADT: 2,988

MUD LAKE ROAD

Good

Over: MUD LAKE CREEK

6.75 MI SE OF LAKE LINDEN, Houghton, MI

Built 2022 Load: 58.6 t ADT: 43

CANAL RD

Good

Over: SCHLOT CREEK

250 FT S OF EILOLA RD, Houghton, MI

Built 2018 Load: 59.6 t ADT: 880

POINT MILLS RD

Good

Over: GOOSENECK CREEK

DOLLAR BAY, Houghton, MI

Built 2021 Load: 62.5 t ADT: 1,778

BEACON HIL TOIVOLA

Good

Over: E BR GRAVERAET RIVER

1 MI S OF HEIKKINEN SCHL, Houghton, MI

Built 2019 Load: 72.3 t ADT: 50

COUNTY ROAD L134

Good

Over: GREEN CREEK

1.5 MI S 1 MI W OF NISULA, Houghton, MI

Built 1992 Load: 72.9 t ADT: 50

M-203

Good

Over: SWEDE TOWN CREEK

AT CEMETERY ROAD, Houghton, MI

Built 2018 Load: 79.1 t ADT: 2,984

ASKEL RD P109

Good

Over: OTTER RIVER

4 MI NE OF ELO, Houghton, MI

Built 1983 Load: 81.0 t ADT: 170

COUNTY ROAD S10

Good

Over: DOUGLAS CREEK

.1 MI NORTH OF LAKE LINDE, Houghton, MI

Built 1981 Load: 97.2 t ADT: 150

COUNTY RD S554

Good

Over: SALMON TROUT RIVER

0.1 MI W REDRIDGE, Houghton, MI

Built 1979 Load: 97.2 t ADT: 250

ASKEL RD P109

Good

Over: OTTER RIVER

4 MI NE OF ELO, Houghton, MI

Built 1983 Load: 97.2 t ADT: 170

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.