Natrona County, WY

138 public highway bridges

Natrona County Bridge Snapshot

Natrona County, Wyoming contains 138 public highway bridges in the FHWA National Bridge Inventory. Roughly 22.5% are rated “Good,” 47.1% “Fair,” 3.6% “Poor,” and 3.6% are classified as structurally deficient — the federal designation for spans whose deck, superstructure, or substructure has been rated 4 or below on the 0–9 NBI scale. Structurally deficient does not mean unsafe to cross; it means the bridge is on the priority list for repair or replacement.

Inspections in WY are conducted by certified engineers from the state Department of Transportation on a 24-month cycle, and results are reported back to the FHWA each spring. The list below shows every NBI-tracked bridge in the county, sorted by inventory load rating. Use the “Sort by” controls to surface the lowest-rated spans first, and click any row for full inspection history, traffic counts, and condition trends.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

138

Total Bridges

22.5%

Good

3.6%

Poor

3.6%

Structurally Deficient

Condition Distribution

Good

22.5% (31)

Fair

47.1% (65)

Poor

3.6% (5)

SD

3.6% (5)

All Bridges (138)

Sort:

I-25 NBL

Over: Na CR 600 (Blackmore)

Casper Marginal, Natrona, WY

Built 1968 ADT: 3,326

I-25 SBL

Over: Na CR 600 (Blackmore)

Casper Marginal, Natrona, WY

Built 1968 ADT: 3,326

BNSF Railway

Over: I-25

Casper, Natrona, WY

Built 1958 ADT: 12,268

N Beverly Street

Over: I-25

Casper Marginal, Natrona, WY

Built 1960 ADT: 12,268

I-25 NBL

Over: North McKinley Street

Casper Marginal, Natrona, WY

Built 1958 ADT: 1,829

I-25 NBL

Over: Wardwell Road Intg

Casper Marginal, Natrona, WY

Built 1964 ADT: 2,344

I-25 SBL

Over: Wardwell Road Intg

Casper Marginal, Natrona, WY

Built 1964 ADT: 4,717

I-25 NBL

Over: Westwinds Road

Casper Marginal, Natrona, WY

Built 1964 ADT: 583

I-25 SBL

Over: Westwinds Road

Casper Marginal, Natrona, WY

Built 1964 ADT: 583

I-25 NBL

Over: Ormsby Road

Casper - Kaycee, Natrona, WY

Built 1971 ADT: 83

I-25 SBL

Over: Ormsby Road

Casper - Kaycee, Natrona, WY

Built 1971 ADT: 83

Hereford Lane

Over: I-25

Casper Marginal, Natrona, WY

Built 1960 ADT: 11,987

US 20/26 Conn. EBL

Over: Na County Road 129

Casper, Natrona, WY

Built 1960 ADT: 105

US 20/26 Conn. WBL

Over: Na County Road 129

Casper, Natrona, WY

Built 1960 ADT: 105

WYO 253

Over: I-25

Casper Marginal, Natrona, WY

Built 1968 ADT: 4,702

US 20/26/87

Over: I-25

Casper Marginal, Natrona, WY

Built 1968 ADT: 12,268

BNSF Railway

Over: North Center Street

Center Street Casper, Natrona, WY

Built 1941 ADT: 7,099

Shepperson Road

Over: I-25

Casper - Kaycee, Natrona, WY

Built 1980 ADT: 1,464

I-25 SBL

Over: Na CR 115 (Smokey Gap)

Casper - Kaycee, Natrona, WY

Built 1980 ADT: 8

I-25 NBL

Over: WYO 387

Casper - Kaycee, Natrona, WY

Built 1980 ADT: 427

I-25 NBL

Over: I-25 Service Road

Casper - Kaycee, Natrona, WY

Built 1980 ADT: 5

I-25 SBL

Over: I-25 Service Road

Casper - Kaycee, Natrona, WY

Built 1980 ADT: 5

I-25 SBL

Over: North McKinley Street

Casper Marginal, Natrona, WY

Built 1958 ADT: 1,829

I-25 SBL

Over: North Center Street

Casper Marginal, Natrona, WY

Built 1958 ADT: 7,099

Unnamed Road

Over: I-25

Casper - Kaycee, Natrona, WY

Built 1981 ADT: 1,515

I-25 NBL

Over: WYO 259

Casper - Kaycee, Natrona, WY

Built 1976 ADT: 3,812

I-25 SBL

Over: WYO 259

Casper - Kaycee, Natrona, WY

Built 1976 ADT: 1,106

BNSF Railway

Over: North McKinley Street

McKinley Street Casper, Natrona, WY

Built 1945 ADT: 4,863

I-25 NBL

Over: US 20 / 26 Connector

Casper Marginal, Natrona, WY

Built 1984 ADT: 1,672

I-25 SBL

Over: US 20 / 26 Connector

Casper Marginal, Natrona, WY

Built 1984 ADT: 4,485

I-25 NBL

Over: WYO 220

Casper Marginal, Natrona, WY

Built 1985 ADT: 14,551

I-25 SBL

Over: WYO 220

Casper Marginal, Natrona, WY

Built 1985 ADT: 14,551

Ranch Road

Over: I-25

Casper - Kaycee, Natrona, WY

Built 2002 ADT: 1,464

I-25 NBL

Over: WYO 258 (Wyoming Blvd)

Casper Marginal, Natrona, WY

Built 2006 ADT: 12,576

I-25 SBL

Over: WYO 258 (Wyoming Blvd)

Casper Marginal, Natrona, WY

Built 2007 ADT: 12,576

WYO 254

Over: US 20 / 26 Connector

Casper, Natrona, WY

Built 2015 ADT: 5,629

I-25 NBL and SBL

Over: Walsh Drive

Casper Marginal, Natrona, WY

Built 2022 ADT: 5,717

Na Cnty Rd 412

Over: Mowrey Draw

3 Mi N.E. Of Alcova, Natrona, WY

Built 1929 Load: 14.3 t ADT: 87

Na Cnty Rd 209

Over: M Casper Creek

0.30 Miles S. Of Natrona, Natrona, WY

Built 1970 Load: 20.2 t ADT: 23

6902: PATHFINDER R

Over: NORTH PLATTE RIVER

10 miles SW of Alcova, WY, Natrona, WY

Built 1995 Load: 23.7 t ADT: 70

US 20 Service Road

Over: Elkhorn Creek

East Yellowstone - Casper, Natrona, WY

Built 1957 Load: 23.9 t ADT: 180

Na Cnty Rd 117

Over: Unnamed Draw

1 Mile East Of Edgerton, Natrona, WY

Built 1967 Load: 26.1 t ADT: 6

Na Cnty Rd 110

Over: Cloud Creek

18 Miles N. Of Natrona, Natrona, WY

Built 1924 Load: 27.8 t ADT: 1,055

US 20/26/87

Over: Claude Creek

East Yellowstone - Casper, Natrona, WY

Built 1957 Load: 28.1 t ADT: 2,833

WYO 220

Over: Eagle Creek

Muddy Gap Jct-WYO 487 Jct, Natrona, WY

Built 1967 Load: 29.9 t ADT: 3,066

WYO 487

Over: Sand Creek

Medicine Bow - Jt WYO 220, Natrona, WY

Built 1981 Load: 29.9 t ADT: 832

Na Cnty Rd 402

Over: Corral Creek

16 Miles S. Of Casper, Natrona, WY

Built 1970 Load: 30.4 t ADT: 23

I-25 Service Road

Over: Dugout Creek

WYO 387 Jct - Buffalo, Natrona, WY

Built 1957 Load: 30.7 t ADT: 5

WYO 220

Over: Dry Creek

Muddy Gap Jct-WYO 487 Jct, Natrona, WY

Built 1970 Load: 30.8 t ADT: 1,771

WYO 254

Over: Casper Creek

Salt Creek Conn Casper, Natrona, WY

Built 1979 Load: 30.8 t ADT: 4,809

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

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Data sourced from official U.S. government datasets. See our methodology for details. Retrieved and formatted by PlainBridges Editorial

Reviewed byPlainbridges Editorial, Plain Bridges Editorial Team · June 5, 2026