County profile · official public datasets

Iron County, WI

48 public highway bridges tracked in the FHWA National Bridge Inventory: 56.3% rated Good, 35.4% Fair, 8.3% Poor.

48
Public bridges
56.3%
Good condition
8.3%
Poor condition

The verdict

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

Iron County posts a higher-than-median Poor-condition share among rated counties in the state across rated county bridge inventory.

50th
of 72 on Poor share
8.3%
Poor-condition share
48
public highway bridges
1986
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.

Iron County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Iron County ranks #50 of 72 Wisconsin counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 8.3%). Iron County, Wisconsin contains 48 public highway bridges. Roughly 56.3% are rated “Good,” 35.4% “Fair,” and 8.3% “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

48

Public highway bridges in Iron County

Good condition

56.3%

27 of 48 rated 7-9

Fair condition

35.4%

17 of 48 rated 5-6

Poor condition

8.3%

4 of 48 rated 4 or below

In-state Poor-share rank

#50 of 72

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

Condition distribution

Share of 48 NBI-tracked bridges by lowest applicable component rating.

Good
56.3% (27)
Fair
35.4% (17)
Poor
8.3% (4)

Iron County's Poor-condition bridges carry 869 vehicle crossings a day

That is 2.1% of the county's reported daily bridge traffic on 8.3% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 217 crossings a day against 729 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 48 of 48 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

25% of Iron County's bridges have passed the 50-year mark

12 of the 48 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 56.3% 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 89.8% of the county's Poor-condition bridge traffic

CTH FF over TURTLE RIVER, built 1967, carries 780 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 4-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 869 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Iron County's bridges were built

48 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 2010s, when 11 of the county's bridges still in the inventory were built, which is 22.9% of those with a recorded year. That cohort is now 5 to 14 years old in the 2024 inventory. Its average build year (1986) matches the Wisconsin average (1984).

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

How Iron County compares with Wisconsin's closest counties by inventory size

The 5 Wisconsin counties nearest Iron County in number of bridges, with their condition splits. Its 8.3% Poor share is the 5th-lowest of these 6. Its average build year of 1986 against a peer-group mean of 1985 is in line with the group.

Showing the 5 closest of 71 Wisconsin counties eligible for comparison.

Bridge inventory size and condition shares for Iron County and the 5 Wisconsin counties closest to it in inventory size
County Bridges Poor
Forest County 53 13.2%
Waushara County 53 5.7%
Washburn County 49 0%
Green Lake County 48 2.1%
Iron County (this page) 48 8.3%
Adams County 41 2.4%

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

Similar inventory size

Nearest county inventories outside WI (48 bridges here).

Similar average build year

Nearest mean year-built outside WI (1986 here).

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

All 48 Good 27 Fair 17 Poor 4

Good-condition bridges (27)

LRD DUPONT RD

Good

Over: MONTREAL RIVER

4.5M N JCT CTH C, Iron, WI

Built 2003 Load: 29.2 t ADT: 111

STH 122

Good

Over: LAWRENCE CR

7.8 M N JCT CTH E, Iron, WI

Built 2011 Load: 32.4 t ADT: 280

CTH A

Good

Over: ORONTO CREEK

1.3M W JCT STH 122, Iron, WI

Built 2018 Load: 33.7 t ADT: 265

LRD ISLAND LAKE RD

Good

Over: W FK MONTREAL RIVER

9.5M W JCT USH 51, Iron, WI

Built 1991 Load: 34.0 t ADT: 77

CTH E

Good

Over: ALDER CREEK

2.3 MI E STH 122, Iron, WI

Built 2009 Load: 35.3 t ADT: 214

LRD POPKO CIRCLE W

Good

Over: TRUDE LAKE

3 MILES SOUTH OF CTH FF, Iron, WI

Built 2014 Load: 35.3 t ADT: 471

LRD CRAMER LAKE RD

Good

Over: TURTLE RIVER

0.3M W JCT CTH H, Iron, WI

Built 2018 Load: 36.0 t ADT: 100

CTH G

Good

Over: LONG LAKE OUTLET

0.5M N JCT CTH H, Iron, WI

Built 2019 Load: 36.6 t ADT: 100

LRD WEBER RD

Good

Over: WEBER CREEK

0.8M S JCT USH 51, Iron, WI

Built 2001 Load: 37.3 t ADT: 30

IRR BIA RTE 1010

Good

Over: BEAR RIVER

17KM N OF LAC DU FLAMBEAU, Iron, WI

Built 2004 Load: 37.5 t ADT: 50

IRR BIA RTE 10

Good

Over: FLAMBEAU BEAR RIVER

13KM N OF LAC DU FLAMBEAU, Iron, WI

Built 1996 Load: 37.6 t ADT: 50

USH 51

Good

Over: WEBER CREEK

3.5 MILES NORTH OF MERCE, Iron, WI

Built 2017 Load: 37.9 t ADT: 2,200

STH 47

Good

Over: LOST CREEK

250 EAST OF INTERSECTION, Iron, WI

Built 2016 Load: 37.9 t ADT: 760

LRD POPLAR ST

Good

Over: MONTREAL RIVER

0.1M E JCT USH 51, Iron, WI

Built 2010 Load: 38.6 t ADT: 5,591

USH 2

Good

Over: SOO LINE

0.8M E JCT STH 122, Iron, WI

Built 1976 Load: 38.9 t ADT: 3,700

LRD FISCHER LAKE R

Good

Over: TURTLE RIVER

0.5M E JCT CTH H, Iron, WI

Built 2001 Load: 38.9 t ADT: 103

LRD HENDRICKSON RD

Good

Over: BOOMER CREEK

1.7M E JCT CTH B, Iron, WI

Built 2004 Load: 38.9 t ADT: 108

STH 122

Good

Over: MONTREAL RIVER

0.6M N JCT CTH A, Iron, WI

Built 1928 Load: 38.9 t ADT: 200

LRD LAKEHEAD RD

Good

Over: BOOMER CREEK

2.2M N JCT USH 2, Iron, WI

Built 1995 Load: 40.5 t ADT: 98

STH 169

Good

Over: POTATO RIVER

13.9M N JCT STH 13, Iron, WI

Built 1998 Load: 40.5 t ADT: 270

LRD NYLUND ROAD

Good

Over: MONTREAL RIVER

TOWN OF KIMBALL, Iron, WI

Built 1991 Load: 40.5 t ADT: 56

CTH H

Good

Over: TURTLE RIVER

4.5M N JCT USH 51, Iron, WI

Built 1996 Load: 42.1 t ADT: 537

LRD APPLE CREEK RD

Good

Over: POTATO RIVER

1.5M S JCT STH 77, Iron, WI

Built 2018 Load: 43.7 t ADT: 20

STH 182

Good

Over: BEAR RIVER

1.8 MILES WEST OF STH 182, Iron, WI

Built 2016 Load: 46.0 t ADT: 460

STH 169

Good

Over: VAUGHN CR

0.75M N RAILROAD TRESTLE, Iron, WI

Built 2016 Load: 47.6 t ADT: 270

LRD UPSON PARK RD

Good

Over: POTATO RIVER

0.2M W JCT STH 122, Iron, WI

Built 1991 Load: 53.5 t ADT: 52

USH 2

Good

Over: W BR MONTREAL RIVER

5.2M E JCT CTH B, Iron, WI

Built 1974 Load: 66.4 t ADT: 3,500

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.