County profile · official public datasets

Lake County, MN

90 public highway bridges tracked in the FHWA National Bridge Inventory: 51.1% rated Good, 36.7% Fair, 12.2% Poor.

90
Public bridges: 51.1%
Good condition: 12.2%
Poor condition

The verdict

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

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

86th
of 87 on Poor share: 12.2%
Poor-condition share: 90
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.

Lake County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Lake County ranks #86 of 87 Minnesota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 12.2%). Lake County, Minnesota contains 90 public highway bridges. Roughly 51.1% are rated “Good,” 36.7% “Fair,” and 12.2% “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

Public highway bridges in Lake County

Good condition

51.1%

46 of 90 rated 7-9

Fair condition

36.7%

33 of 90 rated 5-6

Poor condition

12.2%

11 of 90 rated 4 or below

In-state Poor-share rank

#86 of 87

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

Condition distribution

Share of 90 NBI-tracked bridges by lowest applicable component rating.

Good

51.1% (46)

Fair

36.7% (33)

Poor

12.2% (11)

Lake County's Poor-condition bridges carry 3,710 vehicle crossings a day

That is 3.8% of the county's reported daily bridge traffic on 12.2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 337 crossings a day against 1,167 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 90 of 90 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

38.9% of Lake County's bridges have passed the 50-year mark

35 of the 90 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 51.1% 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 80.9% of the county's Poor-condition bridge traffic

MN 61 over MANITOU RIVER, built 1956, carries 3,000 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 11-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 3,710 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

3
1940s

2
1950s

15
1960s

6
1970s

18
1980s

10
1990s

6
2000s

12
2010s

9
2020s

9

What this shows Construction peaked in the 1970s, when 18 of the county's bridges still in the inventory were built, which is 20% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1984) matches the Minnesota average (1986).

How Lake County compares with Minnesota's closest counties by inventory size

The 5 Minnesota counties nearest Lake County in number of bridges, with their condition splits. Its 12.2% Poor share is the 6th-lowest of these 6. Its average build year of 1984 against a peer-group mean of 1985 is in line with the group.

Showing the 5 closest of 86 Minnesota counties eligible for comparison.

Bridge inventory size and condition shares for Lake County and the 5 Minnesota counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Swift County	97	75.3%	23.7%	1%	1993
Aitkin County	96	55.2%	36.5%	8.3%	1985
Kandiyohi County	94	48.9%	43.6%	7.4%	1980
Lake County (this page)	90	51.1%	36.7%	12.2%	1984
Cass County	85	47.1%	48.2%	4.7%	1985
Waseca County	83	28.9%	62.7%	8.4%	1983

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

Similar inventory size

Nearest county inventories outside MN (90 bridges here).

Greenlee County, AZ · 90 bridges
Clay County, FL · 90 bridges
Taylor County, FL · 90 bridges
Monroe County, GA · 90 bridges

Similar average build year

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

Duval County, FL · avg 1984 · 831 bridges
El Paso County, CO · avg 1984 · 686 bridges
Bell County, TX · avg 1984 · 660 bridges
Steuben County, NY · avg 1984 · 627 bridges

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

All 90 Good 46 Fair 33 Poor 11

All bridges (90)

Sort:

Lake County Bridge Snapshot

Condition distribution

Lake County's Poor-condition bridges carry 3,710 vehicle crossings a day

38.9% of Lake County's bridges have passed the 50-year mark

One structure carries 80.9% of the county's Poor-condition bridge traffic

How Lake County compares with Minnesota'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 (90)

MN 1

MN 1

MN 61

MN 61

MN 1

CSAH 61

CSAH 15

CSAH 11

CSAH 3

CSAH 2

CSAH 2

CSAH 15

MN 169

CSAH 2

T 175

CSAH 4

CSAH 5

MN 61

CSAH 9

MN 61

LAKE 29 EAST ROAD

MN 61

Shoepack Lake Rd

Missabe Rd

CSAH 4

MN 1

TRAPPERS LAKE RD

MN 61

ARROWHEAD CR. RD

CR 102

SPR 20

CSAH 7

CR 705

CSAH 8

L.ISABELLA R. ROAD

TOMAHAWK ROAD

MN 61

VICTOR LAKE ROAD

CSAH 34

T 14

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