Total bridges
58
Public highway bridges in Houghton County
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.
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
- 1900s 1
1900–1909
1 bridges
- 1910s 1
1910–1919
1 bridges
- 1920s 1
1920–1929
1 bridges
- 1930s 3
1930–1939
3 bridges
- 1940s 1
1940–1949
1 bridges
- 1950s
1950–1959
6 bridges
- 1960s 2
1960–1969
2 bridges
- 1970s 4
1970–1979
4 bridges
- 1980s
1980–1989
15 bridges
- 1990s 4
1990–1999
4 bridges
- 2000s
2000–2009
7 bridges
- 2010s
2010–2019
8 bridges
- 2020s 5
2020–2029
5 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.
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.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Gladwin County | 63 | 47.6% | 46% | 6.3% | 1981 |
| Mackinac County | 63 | 25.4% | 55.6% | 19% | 1966 |
| Houghton County (this page) | 58 | 63.8% | 32.8% | 3.4% | 1984 |
| Crawford County | 54 | 14.8% | 66.7% | 18.5% | 1971 |
| Iron County | 54 | 20.4% | 59.3% | 20.4% | 1967 |
| Schoolcraft County | 54 | 27.8% | 66.7% | 5.6% | 1967 |
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).
- Wrangell City and County, AK · 58 bridges
- Jeff Davis County, GA · 58 bridges
- Putnam County, GA · 58 bridges
- Union County, IN · 58 bridges
Similar average build year
Nearest mean year-built outside MI (1984 here).
- Hennepin County, MN · avg 1984 · 936 bridges
- Duval County, FL · avg 1984 · 831 bridges
- El Paso County, CO · avg 1984 · 686 bridges
- Bell County, TX · avg 1984 · 660 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (19)
COUNTY ROAD D162
FairOver: STONY RIVER
4.5 MI S 3.5 MI E KENTON, Houghton, MI
Built 1954 Load: 9.0 t ADT: 50
COUNTY ROAD D163C
FairOver: DEAD STREAM
1.5 MI E 6 MI S OF SIDNAW, Houghton, MI
Built 1954 Load: 12.0 t ADT: 70
FOREST ROAD 2270
FairOver: STURGEON RIVER
S END OF PRICKETT LAKE, Houghton, MI
Built 1954 Load: 22.0 t ADT: 50
US-41
FairOver: PILGRIM RIVER
2.8 MI SE OF HOUGHTON, Houghton, MI
Built 1916 Load: 24.3 t ADT: 5,543
ASKEL RD P109
FairOver: OTTER RIVER
4 MI NE OF ELO, Houghton, MI
Built 1983 Load: 25.9 t ADT: 170
US-41&M-26 RR(ABN)
FairOver: PORTAGE LAKE & EB M-26
HOUGHTON HANCOCK, Houghton, MI
Built 1960 Load: 26.6 t ADT: 24,754
BOOTJACK RD S641
FairOver: TRAP ROCK RIVER
.5 MI E OF LAKE LINDEN, Houghton, MI
Built 1975 Load: 32.4 t ADT: 1,937
BIG TRAVERSE ROAD
FairOver: SLOUGH OUTLET TO LAKE SU
2 MI S 8 MI E LAKE LINDEN, Houghton, MI
Built 1987 Load: 32.4 t ADT: 100
M-28
FairOver: JUMBO CREEK
1.6 MI W OF KENTON, Houghton, MI
Built 1949 Load: 35.6 t ADT: 2,303
BOOTJACK RD T641
FairOver: MCCALLUM CREEK
3 MI S OF LAKE LINDEN, Houghton, MI
Built 1980 Load: 36.0 t ADT: 864
STURGEON RIVER RD
FairOver: STURGEON RIVER
2.0 MI SO OF CHASSELL, Houghton, MI
Built 1979 Load: 36.8 t ADT: 25
M-38
FairOver: W BR STURGEON RIVER
2.7 MI W OF BARAGA COL, Houghton, MI
Built 1934 Load: 37.6 t ADT: 679
US-41
FairOver: STURGEON RIVER
1.8 MI SE OF CHASSEL, Houghton, MI
Built 1960 Load: 38.6 t ADT: 3,883
US-41
FairOver: SNAKE RIVER BURIED
3.7 MI SE OF CHASSEL, Houghton, MI
Built 1934 Load: 38.9 t ADT: 3,883
US-41
FairOver: STURGEON RIVER SLOUGH
2.3 MI SE OF CHASSEL, Houghton, MI
Built 1956 Load: 39.9 t ADT: 3,985
M-28
FairOver: E BR ONTONAGON RIVER
IN KENTON, Houghton, MI
Built 1936 Load: 41.5 t ADT: 1,658
US-41
FairOver: PIKE RIVER
0.7 MI S OF CHASSEL, Houghton, MI
Built 1954 Load: 43.1 t ADT: 3,883
FDR3500
FairOver: E BR ONTONAGON RIVER
8 MI SW OF SIDNAW, Houghton, MI
Built 2021 Load: 45.0 t ADT: 20
US-41
FairOver: BACKWATER PORTAGE RIVER
2.7 MI SE OF CHASSEL, Houghton, MI
Built 1929 Load: 82.3 t ADT: 3,883
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.