County profile · official public datasets

Chisago County, MN

61 public highway bridges tracked in the FHWA National Bridge Inventory: 50.8% rated Good, 47.5% Fair, 1.6% Poor.

61
Public bridges: 50.8%
Good condition: 1.6%
Poor condition

The verdict

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

Chisago County posts a top-quartile lowest Poor-condition share among rated counties in the state across rated county bridge inventory.

Top 15%
lowest Poor share in state: 1.6%
Poor-condition share: 61
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.

Chisago County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Chisago County ranks #13 of 87 Minnesota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 1.6%). Chisago County, Minnesota contains 61 public highway bridges. Roughly 50.8% are rated “Good,” 47.5% “Fair,” and 1.6% “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 Chisago County

Good condition

50.8%

31 of 61 rated 7-9

Fair condition

47.5%

29 of 61 rated 5-6

Poor condition

1.6%

1 of 61 rated 4 or below

In-state Poor-share rank

#13 of 87

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

Condition distribution

Share of 61 NBI-tracked bridges by lowest applicable component rating.

Good

50.8% (31)

Fair

47.5% (29)

Poor

1.6% (1)

Chisago County's Poor-condition bridges carry 5,686 vehicle crossings a day

That is 2.5% of the county's reported daily bridge traffic on 1.6% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 5,686 crossings a day against 2,904 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 61 of 61 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

37.7% of Chisago County's bridges have passed the 50-year mark

23 of the 61 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 50.8% 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 100% of the county's Poor-condition bridge traffic

MN 243 over ST CROIX RIVER, built 1953, carries 5,686 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 1-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 5,686 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

1
1930s

2
1940s

3
1950s

4
1960s

11
1970s

8
1980s

2
1990s

5
2000s

6
2010s

15
2020s

4

What this shows Construction peaked in the 2010s, when 15 of the county's bridges still in the inventory were built, which is 24.6% 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 Minnesota average (1986).

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

The 5 Minnesota counties nearest Chisago County in number of bridges, with their condition splits. Its 1.6% Poor share is the 1st-lowest of these 6. Its average build year of 1986 against a peer-group mean of 1984 is in line with the group.

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

Bridge inventory size and condition shares for Chisago County and the 5 Minnesota counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Le Sueur County	68	45.6%	50%	4.4%	1978
Meeker County	63	50.8%	44.4%	4.8%	1982
Lake of the Woods County	62	61.3%	30.6%	8.1%	1989
Chisago County (this page)	61	50.8%	47.5%	1.6%	1986
Red Lake County	59	67.8%	30.5%	1.7%	1985
Cook County	58	55.2%	39.7%	5.2%	1988

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

Similar inventory size

Nearest county inventories outside MN (61 bridges here).

Amador County, CA · 61 bridges
Cheyenne County, CO · 61 bridges
Montezuma County, CO · 61 bridges
Atkinson County, GA · 61 bridges

Similar average build year

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

El Paso County, TX · avg 1986 · 783 bridges
Caddo County, LA · avg 1986 · 682 bridges
Weld County, CO · avg 1986 · 614 bridges
Polk County, IA · avg 1986 · 545 bridges

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

All 61 Good 31 Fair 29 Poor 1

All bridges (61)

Sort:

Chisago County Bridge Snapshot

Condition distribution

Chisago County's Poor-condition bridges carry 5,686 vehicle crossings a day

37.7% of Chisago County's bridges have passed the 50-year mark

One structure carries 100% of the county's Poor-condition bridge traffic

How Chisago 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 (61)

T 190

CSAH 3

T 368

T 1098

CSAH 30

T 57

M 4

CR 56

US 8

CSAH 40

MN 95

MN 95

MN 95

I 35

CON 4081

CSAH 7

CSAH 19

M 10

US 61

CSAH 1

CSAH 10

M 8

US 8

CSAH 9

CSAH 30

MN 95

CSAH 19

CSAH 30

CSAH 30

US 61

MN 95

CR 81

CR 67

T 33

CSAH 39

M 221

CR 56

CR 85

MSAS 132

CR 93

T 187

CSAH 14

CR 70

CSAH 31

MSAS 122

CSAH 11

CSAH 9

T 150

CSAH 22

M 16

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