County profile · official public datasets

Aitkin County, MN

96 public highway bridges tracked in the FHWA National Bridge Inventory: 55.2% rated Good, 36.5% Fair, 8.3% Poor.

96
Public bridges: 55.2%
Good condition: 8.3%
Poor condition

The verdict

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

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

78th
of 87 on Poor share: 8.3%
Poor-condition share: 96
public highway bridges: 1985
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.

Aitkin County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Aitkin County ranks #78 of 87 Minnesota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 8.3%). Aitkin County, Minnesota contains 96 public highway bridges. Roughly 55.2% are rated “Good,” 36.5% “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

Public highway bridges in Aitkin County

Good condition

55.2%

53 of 96 rated 7-9

Fair condition

36.5%

35 of 96 rated 5-6

Poor condition

8.3%

8 of 96 rated 4 or below

In-state Poor-share rank

#78 of 87

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

Condition distribution

Share of 96 NBI-tracked bridges by lowest applicable component rating.

Good

55.2% (53)

Fair

36.5% (35)

Poor

8.3% (8)

Aitkin County's Poor-condition bridges carry 1,731 vehicle crossings a day

That is 1.6% 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 216 crossings a day against 1,130 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 96 of 96 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

26% of Aitkin County's bridges have passed the 50-year mark

25 of the 96 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 55.2% 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 42.2% of the county's Poor-condition bridge traffic

CSAH 22 over WAKEFIELD BROOK, built 1960, carries 730 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 8-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 1,731 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

1
1930s

6
1950s

6
1960s

6
1970s

15
1980s

19
1990s

10
2000s

22
2010s

7
2020s

4

What this shows Construction peaked in the 2000s, when 22 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 15 to 24 years old in the 2024 inventory. Its average build year (1985) matches the Minnesota average (1986).

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

The 5 Minnesota counties nearest Aitkin County in number of bridges, with their condition splits. Its 8.3% Poor share is the 6th-lowest of these 6. Its average build year of 1985 against a peer-group mean of 1989 is in line with the group.

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

Bridge inventory size and condition shares for Aitkin County and the 5 Minnesota counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Sibley County	102	61.8%	37.3%	1%	1994
Beltrami County	101	63.4%	33.7%	3%	1989
Koochiching County	98	54.1%	38.8%	7.1%	1987
Swift County	97	75.3%	23.7%	1%	1993
Aitkin County (this page)	96	55.2%	36.5%	8.3%	1985
Kandiyohi County	94	48.9%	43.6%	7.4%	1980

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

Similar inventory size

Nearest county inventories outside MN (96 bridges here).

Del Norte County, CA · 96 bridges
Routt County, CO · 96 bridges
Blaine County, ID · 96 bridges
Clare County, MI · 96 bridges

Similar average build year

Nearest mean year-built outside MN (1985 here).

Hillsborough County, FL · avg 1985 · 840 bridges
Lancaster County, NE · avg 1985 · 661 bridges
Nueces County, TX · avg 1985 · 528 bridges
Grayson County, TX · avg 1985 · 513 bridges

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

All 96 Good 53 Fair 35 Poor 8

Good-condition bridges (53)

Sort:

Aitkin County Bridge Snapshot

Condition distribution

Aitkin County's Poor-condition bridges carry 1,731 vehicle crossings a day

26% of Aitkin County's bridges have passed the 50-year mark

One structure carries 42.2% of the county's Poor-condition bridge traffic

How Aitkin 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

Good-condition bridges (53)

RICE LAKE ROAD

SERVICE ROAD

MN 200

MN 47

US 169

US 169

US 169

MN 200

US 169

MN 65

US 169

CSAH 15

MN 210

MN 47

MN 200

CSAH 3

CSAH 14

MN 210

T 216

CR 64

CR 64

CR 67

CR 51

CSAH 29

CR 74

CSAH 3

SFR 52

CSAH 26

CSAH 4

CR 56

CSAH 39

CSAH 9

T 224

T 224

MAIN REFUGE ROAD

T 119

MN 65

US 169

US 169

CSAH 10

T 357

CSAH 3

CSAH 32

CSAH 22

MN 210

T 1382

T 614

CSAH 1

CSAH 18

T 1076

Related