Boulder County, CO

311 public highway bridges

Boulder County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Boulder County, Colorado contains 311 public highway bridges. Roughly 33.4% are rated “Good,” 60.5% “Fair,” and 2.3% “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.

311
Total Bridges
33.4%
Good
60.5%
Fair
2.3%
Poor Condition

Condition Distribution

Good
33.4% (104)
Fair
60.5% (188)
Poor
2.3% (7)

All Bridges (311)

EBND US 36 ML

Unknown

Over: US 36 SPUR/BASELINE RD

IN BOULDER, Boulder, CO

Built 1963 ADT: 30,000

US 36 WBND SPUR

Unknown

Over: US 36 SPUR/BASELINE RD

S end of BOULDER, Boulder, CO

Built 1993 ADT: 30,000

SH 157 ML

Unknown

Over: SH 119 ML

IN BOULDER, Boulder, CO

Built 1988 ADT: 29,000

47TH STREET

Unknown

Over: SH 157 ML

NEAR SH 119 IN BOULDER, Boulder, CO

Built 1989 ADT: 4,761

TABLE MESA DRIVE

Unknown

Over: US 36 ML

IN BOULDER, Boulder, CO

Built 1951 ADT: 17,183

SH 157 RAMP

Unknown

Over: US 36 ML

IN BOULDER, Boulder, CO

Built 1971 ADT: 72,000

SH170 ML(McCaslin)

Unknown

Over: US 36 ML

3.9 MI E OF JCT SH 93, Boulder, CO

Built 1983 ADT: 72,000

EMMA ST.

Unknown

Over: US 287 ML

IN LAFAYETTE, Boulder, CO

Built 1994 ADT: 3,673

CHERRYVALE ROAD

Unknown

Over: SH 36 ML

1.4 MI E OF JCT SH 157, Boulder, CO

Built 2009 ADT: 88,000

WB US 36 ON RAMP

Unknown

Over: WB BUS RAMP/BIKE PATH

MCCASLIN and US 36, Boulder, CO

Built 2016

EB US 36 OFF RAMP

Unknown

Over: EB BUS RAMP

McCASLIN and US 36, Boulder, CO

Built 2016

Pratt Parkway

Unknown

Over: BNRR and 1st Avenue

0.2 Mi N of Boston Ave, Boulder, CO

Built 1980 ADT: 13,813

Co Rd 54A

Fair

Over: Middle Boulder Creek

Castle Rock Pull Off, Boulder, CO

Built 1917 Load: 6.6 t ADT: 66

BOULDER CREEK PATH

Fair

Over: BOULDER CREEK

4Mi Canyon Path at SH119, Boulder, CO

Built 2020 Load: 8.0 t ADT: 11

SH 157 ML

Fair

Over: PEARL STREET

2.9 MI N OF US 36, Boulder, CO

Built 1985 Load: 8.2 t ADT: 43,000

SH 157 ML

Fair

Over: BNSF RR

IN BOULDER, Boulder, CO

Built 1981 Load: 10.9 t ADT: 43,000

Oxford Rd (Cr 26)

Fair

Over: Boulder Feeder Ditch

0.3 Mi W of Co Rd 41, Boulder, CO

Built 1950 Load: 13.4 t ADT: 422

SH 93 ML

Fair

Over: SOUTH BOULDER CREEK

0.4 MI N OF JCT SH 170 +, Boulder, CO

Built 1969 Load: 14.0 t ADT: 17,000

US 36 ML EBND

Fair

Over: BOULDER CREEK

IN BOULDER, Boulder, CO

Built 1960 Load: 15.0 t ADT: 18,000

US 287 ML

Fair

Over: DRY CREEK

Ken Pratt Blvd-Longmont, Boulder, CO

Built 1947 Load: 16.5 t ADT: 22,000

SH 119 ML

Fair

Over: BOULDER CREEK

13.7 MI E OF JCT SH 72, Boulder, CO

Built 1953 Load: 17.1 t ADT: 6,400

SH 119 ML

Fair

Over: BOULDER CREEK

JUST WEST OF BOULDER, Boulder, CO

Built 1953 Load: 18.1 t ADT: 6,400

120TH STREET

Fair

Over: Rock Creek

0.5 Mi S of S. Boulder Rd, Boulder, CO

Built 1986 Load: 18.2 t ADT: 3,390

County Road 47

Fair

Over: St. Vrain Supply Canal

2.7 Mi N of St Hwy 66, Boulder, CO

Built 1997 Load: 18.7 t ADT: 316

County Road 130

Fair

Over: Middle Boulder Creek

2.5 Mi W of St Hwy 72, Boulder, CO

Built 1990 Load: 19.4 t ADT: 742

Rogers Road

Fair

Over: Lykin Gulch

0.25 Mi W of Airport Rd, Boulder, CO

Built 2000 Load: 20.9 t ADT: 80

SH 72 ML

Fair

Over: MIDDLE ST VRAIN CREEK

7 MI NORTH OF WARD, Boulder, CO

Built 1959 Load: 21.0 t ADT: 1,400

SH 170 ML

Fair

Over: SOUTH BOULDER CREEK

0.9 MI W. OF EL DORADO SP, Boulder, CO

Built 1930 Load: 21.0 t ADT: 388

SH 7 ML

Fair

Over: BEAR CANYON CREEK

JCT 157 & ARAPAHOE, Boulder, CO

Built 1985 Load: 22.4 t ADT: 29,000

Folsom Street

Fair

Over: Goose Creek

300 Ft. So. of Valmont, Boulder, CO

Built 1970 Load: 22.6 t ADT: 10,980

US 287 ML

Fair

Over: LEFT HAND CREEK

IN LONGMONT, Boulder, CO

Built 1948 Load: 22.6 t ADT: 24,000

St Vrain Road CR16

Fair

Over: Boulder Feeder Ditch

0.5 Mi E of Co Rd 51, Boulder, CO

Built 1955 Load: 22.7 t ADT: 1,009

SH 170 ML

Fair

Over: COMMUNITY DITCH

E ENT ELDORADO STATE PARK, Boulder, CO

Built 1999 Load: 22.7 t ADT: 1,300

55th Street

Fair

Over: Empson Ditch

250 Ft N of Penn. Ave., Boulder, CO

Built 1996 Load: 23.1 t ADT: 9,146

US 36 ML

Fair

Over: FOUR MILE CANYON CREEK

28th ST in BOULDER, Boulder, CO

Built 1957 Load: 23.2 t ADT: 16,000

US 36 ML

Fair

Over: SUPPLY DITCH

IN LYONS, Boulder, CO

Built 1972 Load: 23.2 t ADT: 15,000

FDR 298 & BC 116

Fair

Over: NORTH BOULDER CREEK

3.45 MI SW OF CO HWY 72, Boulder, CO

Built 1970 Load: 23.3 t ADT: 40

SH 157 ML

Fair

Over: BEAR CANYON CREEK

NEAR COLORADO AVE., Boulder, CO

Built 1978 Load: 24.2 t ADT: 38,000

C. R. 41 (63rd St)

Fair

Over: St. Vrain Creek

0.5 Mi N of Co Rd 10, Boulder, CO

Built 1991 Load: 24.3 t ADT: 134

Boston Ave (Cr 18)

Fair

Over: St. Vrain Creek

0.1 Mi E of Co Rd 15, Boulder, CO

Built 1990 Load: 24.4 t ADT: 9,636

Brockway Drive

Fair

Over: Goodhue Ditch

0.1 Mi E of 76th Street, Boulder, CO

Built 1962 Load: 24.5 t ADT: 6,900

Co Rd 54A

Fair

Over: Middle Boulder Creek

Castle Rock Pull Off, Boulder, CO

Built 1917 Load: 24.5 t ADT: 70

Rock Creek Pkwy.

Fair

Over: Rock Creek

0.3 Mi N of Coalton D, Boulder, CO

Built 1999 Load: 24.5 t ADT: 11,360

SH 72 ML

Fair

Over: SOUTH ST VRAIN CREEK

3.8 MI NORTH OF WARD, Boulder, CO

Built 1959 Load: 24.6 t ADT: 1,100

COUNTY ROAD 116

Fair

Over: BOULDER CREEK

3.3 MI WEST OF ST HWY 72, Boulder, CO

Built 1995 Load: 25.1 t ADT: 74

SH 170 ML

Fair

Over: DAVIDSON DITCH

1.5 MI W OF JCT SH 93, Boulder, CO

Built 1952 Load: 25.4 t ADT: 1,200

County Road 31

Fair

Over: St. Vrain Creek

0.6 Mi S of Co Rd 10, Boulder, CO

Built 1979 Load: 25.5 t ADT: 6,233

SH 93 ML

Fair

Over: BOULDER CREEK

N. of Arapahoe Ave, Boulder, CO

Built 2004 Load: 25.6 t ADT: 22,000

US 36 ML

Fair

Over: CANYON CREEK

IN BOULDER, Boulder, CO

Built 1951 Load: 25.7 t ADT: 45,000

SH 119 ML

Fair

Over: OLIGARCHY DITCH

IN LONGMONT, Boulder, CO

Built 2004 Load: 25.9 t ADT: 24,000
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges

Every figure on PlainBridge 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.