County profile · official public datasets

Todd County, SD

24 public highway bridges tracked in the FHWA National Bridge Inventory: 41.7% rated Good, 29.2% Fair, 29.2% Poor.

Compiled by PlainBridges

24
Public bridges: 41.7%
Good condition: 29.2%
Poor condition

The verdict

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

Todd County pairs a higher-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

61st
of 66 on Poor share: 29.2%
Poor-condition share: 24
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.

Todd County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Todd County ranks #61 of 66 South Dakota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 29.2%). Todd County, South Dakota contains 24 public highway bridges. Roughly 41.7% are rated “Good,” 29.2% “Fair,” and 29.2% “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

24

Public highway bridges in Todd County

Good condition

41.7%

10 of 24 rated 7-9

Fair condition

29.2%

7 of 24 rated 5-6

Poor condition

29.2%

7 of 24 rated 4 or below

In-state Poor-share rank

#61 of 66

Among South Dakota counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 24 NBI-tracked bridges by lowest applicable component rating.

Good

41.7% (10)

Fair

29.2% (7)

Poor

29.2% (7)

Todd County's Poor-condition bridges carry 5,256 vehicle crossings a day

That is 32.9% of the county's reported daily bridge traffic on 29.2% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 751 crossings a day against 228 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 24 of 24 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

37.5% of Todd County's bridges have passed the 50-year mark

9 of the 24 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 41.7% 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 35.2% of the county's Poor-condition bridge traffic

IRR BIA RTE 7 over LITTLE WHITE RIVER, built 1972, carries 1,851 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 7-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 5,256 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1940s

1
1950s

1
1960s

4
1970s

4
1980s

2
1990s

3
2000s

6
2010s

2
2020s

1

What this shows Construction peaked in the 2000s, when 6 of the county's bridges still in the inventory were built, which is 25% of those with a recorded year. That cohort is now 15 to 24 years old in the 2024 inventory. Its average build year is 1986, 11 years newer than the South Dakota average of 1975.

How Todd County compares with South Dakota's closest counties by inventory size

The 5 South Dakota counties nearest Todd County in number of bridges, with their condition splits. Its 29.2% Poor share is the 6th-lowest of these 6. Its average build year of 1986 against a peer-group mean of 1979 is 7 years newer.

Showing the 5 closest of 65 South Dakota counties eligible for comparison.

Bridge inventory size and condition shares for Todd County and the 5 South Dakota counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Dewey County	28	57.1%	28.6%	14.3%	1986
Mellette County	28	32.1%	60.7%	7.1%	1980
Buffalo County	25	32%	64%	4%	1976
Potter County	24	54.2%	45.8%	0%	1981
Todd County (this page)	24	41.7%	29.2%	29.2%	1986
Hyde County	23	34.8%	39.1%	26.1%	1974

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 Todd 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 Todd County, both outside South Dakota so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside SD (24 bridges here).

Meade County, KY · 24 bridges
Robertson County, KY · 24 bridges
Garfield County, NE · 24 bridges
De Baca County, NM · 24 bridges

Similar average build year

Nearest mean year-built outside SD (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 24 Good 10 Fair 7 Poor 7

All bridges (24)

Sort:

295th Ave.

Over: KEYA PAHA RV

13.2S 8.0E OKREEK, Todd, SD

Built 1948 Load: 17.0 t ADT: 27

MAIN STREET

Over: ANTELOPE CK

0.1S MISSION, Todd, SD

Built 1978 Load: 24.0 t ADT: 1,400

IRR US018

Over: WHITE HORSE CK

3.8 W TRIPP CO LINE, Todd, SD

Built 2016 Load: 26.6 t ADT: 1,279

IRR BIA RTE 9

Over: LITTLE WHITE RIVER

4.0 KM N JCT US 18 & RT 9, Todd, SD

Built 1970 Load: 27.2 t ADT: 531

IRR US018

Over: LITTLE WHITE RV

9.2 W JCT US 83 N, Todd, SD

Built 1989 Load: 28.2 t ADT: 1,387

IRR US083

Over: ANTELOPE CK

0.1 S JCT US 18, Todd, SD

Built 1981 Load: 35.2 t ADT: 2,517

IRR US018

Over: TRIB TO OAK CK

9.4 W TRIPP CO LINE, Todd, SD

Built 2005 Load: 99.9 t ADT: 1,279

IRR COUNTY ROAD

Over: PHISTER CK

3.9S & 8W PARMELLE, Todd, SD

Built 2003 Load: 21.8 t ADT: 15

IRR COUNTY ROAD

Over: ANTELOPE CK

1.7S 5.0E MISSION, Todd, SD

Built 1994 Load: 24.5 t ADT: 27

IRR COUNTY ROAD

Over: KEYA PAHA RV

14.2E & 6.0S OF MISSION, Todd, SD

Built 2000 Load: 24.5 t ADT: 20

IRR SD063

Over: CUT MEAT CK

0.3 W OF PARMELEE, Todd, SD

Built 2002 Load: 25.1 t ADT: 609

IRR BIA RTE 4

Over: CUT MEAT CREEK

3KM SW OF PARMALEE, Todd, SD

Built 2004 Load: 33.4 t ADT: 200

BIA RTE 5

Over: LITTLE WHITE RIVER

SPRING CREEK, Todd, SD

Built 2003 Load: 33.5 t ADT: 100

280th Ave.

Over: ANTELOPE CK

1.9S & 6E MISSION, Todd, SD

Built 1994 Load: 36.1 t ADT: 27

IRR BIA RTE 30

Over: LITTLE WHITE RIVER

1.5MI W SPRING CRK SCHOOL, Todd, SD

Built 1994 Load: 36.3 t ADT: 158

IRR BIA RTE 5

Over: LITTLE WHITE RIVER

16 KM NE OF SPRING CREEK, Todd, SD

Built 2016 Load: 36.9 t ADT: 1,096

IRR COUNTY ROAD

Over: ANTELOPE CK

2 S & 6.3 E OF MISSION, Todd, SD

Built 2020 Load: 99.9 t ADT: 27

HIDDEN TIMBER ROAD

Over: ANTELOPE CK

9 E 3.8 S MISSION, Todd, SD

Built 1951 Load: 19.1 t ADT: 128

IRR BIA RTE 7

Over: LITTLE WHITE RIVER

AT GHOST HAWK PARK, Todd, SD

Built 1972 Load: 20.9 t ADT: 1,851

IRR BIA RTE 5

Over: LITTLE WHITE RIVER

5 KM N SPRING CR SCHOOL, Todd, SD

Built 1967 Load: 21.6 t ADT: 1,050

IRR BIA RTE 11

Over: ROSEBUD CREEK

ROSEBUD STREET IN ROSEBUD, Todd, SD

Built 1971 Load: 21.6 t ADT: 114

IRR BIA RTE 5

Over: LITTLE WHITE RIVER

18.4 KM NE SPRING CR SCHL, Todd, SD

Built 1967 Load: 22.8 t ADT: 1,050

IRR BIA RTE 5

Over: LITTLE WHITE RIVER

17.6 KM NE SPRING CR SCH, Todd, SD

Built 1965 Load: 23.9 t ADT: 1,019

IRR BIA RTE 3

Over: LITTLE WHITE RIVER

IN GHOST HAWK PARK, Todd, SD

Built 1964 Load: 24.8 t ADT: 44

Read our methodology - how this data is sourced, computed, and verified.

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Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges

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Compiled by PlainBridges, Independent data publisher

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.