County profile · official public datasets

Niobrara County, WY

34 public highway bridges tracked in the FHWA National Bridge Inventory: 44.1% rated Good, 52.9% Fair, 2.9% Poor.

34
Public bridges
44.1%
Good condition
2.9%
Poor condition

The verdict

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

Niobrara County pairs a top-quartile lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 22%
lowest Poor share in state
2.9%
Poor-condition share
34
public highway bridges
1988
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.

Niobrara County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Niobrara County ranks #5 of 23 Wyoming counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 2.9%). Niobrara County, Wyoming contains 34 public highway bridges. Roughly 44.1% are rated “Good,” 52.9% “Fair,” and 2.9% “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

34

Public highway bridges in Niobrara County

Good condition

44.1%

15 of 34 rated 7-9

Fair condition

52.9%

18 of 34 rated 5-6

Poor condition

2.9%

1 of 34 rated 4 or below

In-state Poor-share rank

#5 of 23

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

Condition distribution

Share of 34 NBI-tracked bridges by lowest applicable component rating.

Good
44.1% (15)
Fair
52.9% (18)
Poor
2.9% (1)

Niobrara County's Poor-condition bridges carry 5 vehicle crossings a day

That is 0% of the county's reported daily bridge traffic on 2.9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 5 crossings a day against 636 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 34 of 34 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

17.6% of Niobrara County's bridges have passed the 50-year mark

6 of the 34 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 44.1% 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 100% of the county's Poor-condition bridge traffic

Ni Cnty Rd 9 over Cheyenne River, built 1920, carries 5 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 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Niobrara County's bridges were built

34 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1980s, when 10 of the county's bridges still in the inventory were built, which is 29.4% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1988, 12 years newer than the Wyoming average of 1976.

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

How Niobrara County compares with Wyoming's closest counties by inventory size

The 5 Wyoming counties nearest Niobrara County in number of bridges, with their condition splits. Its 2.9% Poor share is the 1st-lowest of these 6. Its average build year of 1988 against a peer-group mean of 1975 is 13 years newer.

Showing the 5 closest of 22 Wyoming counties eligible for comparison.

Bridge inventory size and condition shares for Niobrara County and the 5 Wyoming counties closest to it in inventory size
County Bridges Poor
Goshen County 106 3.8%
Big Horn County 91 7.7%
Washakie County 61 9.8%
Weston County 43 9.3%
Hot Springs County 39 5.1%
Niobrara County (this page) 34 2.9%

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

Similar inventory size

Nearest county inventories outside WY (34 bridges here).

Similar average build year

Nearest mean year-built outside WY (1988 here).

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

All bridges (34)

Ni Cnty Rd 6

Fair

Over: Hungry Hollow

6 Mi W. Of Mule Crk Jct, Niobrara, WY

Built 1983 Load: 17.6 t ADT: 33

WYO 272

Fair

Over: Lance Creek

Jct WYO 270 - North, Niobrara, WY

Built 1969 Load: 29.0 t ADT: 27

US 18

Fair

Over: Old Woman Creek

Lusk - Mule Creek Jct, Niobrara, WY

Built 1971 Load: 29.9 t ADT: 2,115

Ni Cnty Rd 11

Fair

Over: Black Creek

12 Mi Sw Of Mule Crk Jct, Niobrara, WY

Built 1981 Load: 32.7 t ADT: 33

US 20

Fair

Over: C and NW Railroad

Lusk-Vantassel Road, Niobrara, WY

Built 1984 Load: 32.7 t ADT: 525

US 18

Fair

Over: Mule Creek

Lusk-Newcastle, Niobrara, WY

Built 1988 Load: 32.7 t ADT: 2,115

US 85

Fair

Over: Robbers Roost Creek

Mule Creek Jct-Newcastle, Niobrara, WY

Built 1992 Load: 32.7 t ADT: 1,079

WYO 270

Fair

Over: Provost Draw

Lance Creek East Section, Niobrara, WY

Built 2004 Load: 32.7 t ADT: 208

Ni Cnty Rd 13

Fair

Over: Lance Creek

2 Miles N.E. Of Cow Creek, Niobrara, WY

Built 1983 Load: 33.6 t ADT: 17

US 18

Fair

Over: Old Woman Creek

Lusk - Newcastle, Niobrara, WY

Built 1987 Load: 34.5 t ADT: 2,115

US 85

Fair

Over: Cheyenne River

Mule Creek Jct-Newcastle, Niobrara, WY

Built 1990 Load: 38.1 t ADT: 1,079

Ni Cnty Rd 14

Fair

Over: Lightning Creek

N. Lance Creek Road, Niobrara, WY

Built 1994 Load: 40.8 t ADT: 29

Ni Cnty Rd 14

Fair

Over: Cow Creek

N. Lance Creek Road, Niobrara, WY

Built 1994 Load: 40.8 t ADT: 29

Ni Cnty Rd 18

Fair

Over: Sage Creek

14 Mi Ne Of Lusk, Niobrara, WY

Built 1997 Load: 44.5 t ADT: 31

WYO 270

Fair

Over: Cherry Creek

Lance Creek-South, Niobrara, WY

Built 1995 Load: 46.3 t ADT: 281

US 20

Fair

Over: Niobrara River

Lusk Streets 3Rd Street, Niobrara, WY

Built 2003 Load: 52.9 t ADT: 970

Ni Cnty Rd 6

Fair

Over: Alkali Creek

3 Mi. Nw Of Mule Crk Jct, Niobrara, WY

Built 1997 Load: 53.5 t ADT: 33

US 18

Fair

Over: Niobrara River

Lusk, Niobrara, WY

Built 1988 Load: 58.1 t ADT: 3,162

Ni Cnty Rd 64

Good

Over: South Indian Creek

8 Miles E. Of Hat Creek, Niobrara, WY

Built 1958 Load: 20.6 t ADT: 40

W Pershing Street

Good

Over: Niobrara River

Lusk Streets, Niobrara, WY

Built 1991 Load: 32.4 t ADT: 314

US 85

Good

Over: UPRR

Lusk Streets, Niobrara, WY

Built 2016 Load: 32.4 t ADT: 3,162

Daley Street

Good

Over: Niobrara River

Lusk, Niobrara, WY

Built 1986 Load: 32.7 t ADT: 340

US 85

Good

Over: Bobcat Creek

Mule Creek Jct-Newcastle, Niobrara, WY

Built 1991 Load: 32.7 t ADT: 1,079

US 18

Good

Over: Stockpass

Orin Jct-Lusk, Niobrara, WY

Built 1970 Load: 32.7 t ADT: 2,387

WYO 270

Good

Over: Unnamed Draw

Manville South, Niobrara, WY

Built 1956 Load: 32.7 t ADT: 275

US 20

Good

Over: S Fork Niobrara River

Lusk - Nebr. State Line, Niobrara, WY

Built 1986 Load: 33.6 t ADT: 525

US 20

Good

Over: Van Tassell Creek

Lusk - Nebr. Line, Niobrara, WY

Built 1986 Load: 34.5 t ADT: 534

Ni Cnty Rd 50

Good

Over: Lightning Creek

Kaye Field Road, Niobrara, WY

Built 1994 Load: 40.8 t ADT: 24

US 20

Good

Over: Niobrara River

Lusk - Nebr Line, Niobrara, WY

Built 2019 Load: 46.0 t ADT: 534

WYO 271

Good

Over: Lance Creek

.17 Mi West Of Lance Cree, Niobrara, WY

Built 2003 Load: 47.2 t ADT: 39

Ni Cnty Rd 11

Good

Over: Lance Creek

12 Mi SW of mule Crk Jct, Niobrara, WY

Built 2017 Load: 48.3 t ADT: 33

WYO 271

Good

Over: Little Lightning Creek

3 Mi West Of Lance Creek, Niobrara, WY

Built 2003 Load: 49.9 t ADT: 39

WYO 270

Good

Over: Old Woman Creek

Lance Creek East Road, Niobrara, WY

Built 2007 Load: 68.0 t ADT: 208

Ni Cnty Rd 9

Poor

Over: Cheyenne River

6 Mi. N.E.Of Mule Crk Jct, Niobrara, WY

Built 1920 Load: 27.1 t ADT: 5
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.