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)

SH 119 ML SBND

Good

Over: LEFT HAND CREEK

3.6 MI N OF JCT SH 52, Boulder, CO

Built 1975 Load: 37.5 t ADT: 14,000

County Road 81

Good

Over: Lefthand Creek

250 ft N of Lee Hill Dr, Boulder, CO

Built 2019 Load: 38.2 t ADT: 735

County Line Road

Good

Over: Spring Gulch #2

0.20 MI N. OF E 9TH AVE, Boulder, CO

Built 2021 Load: 38.6 t ADT: 15,509

96th Street

Good

Over: Coal Creek

0.15 Mi. S. of SH42, Boulder, CO

Built 2006 Load: 38.6 t ADT: 15,821

Flagstaff Rd CR56

Good

Over: HIllside Slide

1.0 Mi W of Baseline Rd, Boulder, CO

Built 2014 Load: 38.9 t ADT: 2,463

SH 119 ML, E.Bnd

Good

Over: LEFT HAND CREEK

3.6 MI NE OF SH 52, Boulder, CO

Built 2003 Load: 38.9 t ADT: 24,000

Anderson Hill St

Good

Over: James Creek

200 Ft S of Main St, Boulder, CO

Built 2016 Load: 38.9 t ADT: 117

Martin Street

Good

Over: Left Hand Creek

0.2 MI S Ken Pratt Blvd, Boulder, CO

Built 2016 Load: 38.9 t ADT: 2,572

N. 95th St (Cr 19)

Good

Over: Liggett Ditch

1.2 Mi S of Co Rd 38, Boulder, CO

Built 1984 Load: 39.6 t ADT: 7,744

US 287 NBND

Good

Over: ROCK CREEK

0.4 MI S of NW PKWY, Boulder, CO

Built 1993 Load: 39.9 t ADT: 16,500

US 287 ML SBND

Good

Over: ROCK CREEK

2.2 MI NO OF JCT SH 121, Boulder, CO

Built 1994 Load: 39.9 t ADT: 16,500

S Pratt Parkway

Good

Over: Left Hand Creek

At Missouri Avenue, Boulder, CO

Built 2012 Load: 40.1 t ADT: 4,798

17th Avenue

Good

Over: Spring Gulch

750 Ft E of Whitehall Dr, Boulder, CO

Built 2000 Load: 40.2 t ADT: 9,396

Valmont Rd

Good

Over: Boulder Creek

200 Ft. E of 55th Street, Boulder, CO

Built 1999 Load: 40.5 t ADT: 14,324

SH 93 ML

Good

Over: Bear Creek Ditch

1/2 MI S OF BOULDER LIMIT, Boulder, CO

Built 1969 Load: 40.8 t ADT: 17,000

95 Street (CR 19)

Good

Over: Boulder Creek

1.7 Mi S of CR28, Boulder, CO

Built 2010 Load: 41.5 t ADT: 7,778

Flagstaff Rd CR56

Good

Over: Hillside Slide

1.0 Mi W of Baseline Rd, Boulder, CO

Built 1996 Load: 41.5 t ADT: 2,463

N 81st St (Cr 31)

Good

Over: Left Hand Creek

0.1 M N of Oxford Rd (26), Boulder, CO

Built 1992 Load: 41.9 t ADT: 182

SH 119 ML, W.Bnd

Good

Over: LEFTHAND CREEK

3.6 MI NE OF SH 52, Boulder, CO

Built 2003 Load: 43.1 t ADT: 24,000

SH 119 ML EBND

Good

Over: ST VRAIN RIVER

NEAR LONGMONT, Boulder, CO

Built 2003 Load: 43.1 t ADT: 12,000

Spring Creek Place

Good

Over: Wonderland Creek

570 ft from 34th St., Boulder, CO

Built 2017 Load: 43.4 t

SH 157 NBND

Good

Over: FOUR MILE CANYON CREEK

TWO MILES N OF BOULDER CI, Boulder, CO

Built 1988 Load: 43.6 t ADT: 20,500

IRIS AVENUE

Good

Over: WONDERLAND CREEK

0.2 MI East of 30th St, Boulder, CO

Built 2020 Load: 43.7 t ADT: 1,988

Arapahoe Avenue

Good

Over: Boulder Creek

0.08 Mi E of S. Broadway, Boulder, CO

Built 1988 Load: 45.3 t ADT: 10,452

US 36 ML

Good

Over: SOUTH BOULDER CREEK

2.4 MI E OF JCT SH 93, Boulder, CO

Built 1951 Load: 45.4 t ADT: 77,000

Wagonwheel Gap Rd

Good

Over: Fourmile Creek

200 ft W of Lee Hill Dr, Boulder, CO

Built 2019 Load: 45.7 t ADT: 630

SH 157 SBND

Good

Over: FOUR MILE CANYON CREEK

.25 MI S OF SH119 INTSN, Boulder, CO

Built 1988 Load: 46.4 t ADT: 20,500

County Road 26

Good

Over: Left Hand Creek

0.6 Mi W of Co Rd 33, Boulder, CO

Built 1991 Load: 46.8 t ADT: 121

Logan Mill Road

Good

Over: Four Mile Creek

20 ft W of Four Mi Cny Dr, Boulder, CO

Built 2019 Load: 47.6 t ADT: 238

Dillon Road

Good

Over: Rock Creek

0.3 Mi W of Hwy 287, Boulder, CO

Built 2019 Load: 47.6 t ADT: 451

N. 63rd St (CR39)

Good

Over: Leggett Ditch

0.4 MI N of SH7, Boulder, CO

Built 2015 Load: 48.0 t ADT: 3,275

Pace Street

Good

Over: Spring Gulch

.15 Mi. N of Wyndemere, Boulder, CO

Built 2000 Load: 49.7 t ADT: 7,639

Hygiene Rd (Cr 10)

Good

Over: Boulder Feeder Ditch

0.7 Mi E of US Hwy 36, Boulder, CO

Built 1987 Load: 50.3 t ADT: 692

N. 119th St (Cr 3)

Good

Over: St. Vrain Creek

0.5 Mi N of Co Rd 20, Boulder, CO

Built 1988 Load: 52.1 t ADT: 3,288

FDR 114

Good

Over: MIDDLE ST. VRAIN CREEK

.2 MI W OF CO HWY 72, Boulder, CO

Built 1952 Load: 52.8 t ADT: 198

US 36 ML

Good

Over: ST VRAIN CREEK

IN LYONS, Boulder, CO

Built 2000 Load: 54.0 t ADT: 8,200

South Sunset St.

Good

Over: Left Hand Creek

200 ft N of Creekside Dr, Boulder, CO

Built 2000 Load: 55.1 t ADT: 1,274

FDR 114

Good

Over: MIDDLE ST. VRAIN CREEK

0.94 MI WEST OF CO HWY 72, Boulder, CO

Built 1952 Load: 56.1 t ADT: 90

Bow Mountain Rd.

Good

Over: Fourmile Creek

20 ft S of Wagonwheel Rd, Boulder, CO

Built 2019 Load: 56.1 t ADT: 124

SH 119 NBND

Good

Over: DRY CREEK

4.5 MI NE OF JCT US 36, Boulder, CO

Built 1959 Load: 60.2 t ADT: 18,500

Olympia Avenue

Good

Over: Spring Gulch

200 feet E of Boise Court, Boulder, CO

Built 2000 Load: 61.0 t ADT: 1,207

Main Street

Good

Over: James Creek

Inter of Main and Mill, Boulder, CO

Built 2018 Load: 64.8 t ADT: 180

County Road 81

Good

Over: James Creek

25 ft S of Lefthand Cyn, Boulder, CO

Built 2019 Load: 65.8 t ADT: 777

CoRd94(LH Cnyn RD)

Good

Over: LEFTHAND CREEK

0.6 Mi W of Oldstage Rd, Boulder, CO

Built 2016 Load: 68.0 t ADT: 1,681

US 287

Good

Over: DRAW

JUST N OF NW PKWY, Boulder, CO

Built 1993 Load: 68.3 t ADT: 39,000

N 115th St

Good

Over: Highland Ditch

0.95 Mi N of Vermillion R, Boulder, CO

Built 2012 Load: 69.3 t ADT: 435

Wagonwheel Gap Rd

Good

Over: Four Mile Creek

0.6 Mi W of Lee Hill Rd, Boulder, CO

Built 2019 Load: 69.7 t ADT: 587

27th Way

Good

Over: Skunk Creek

0.2 Mi No of St Hwy 93, Boulder, CO

Built 2008 Load: 74.8 t ADT: 10,468

SH 52 ML

Good

Over: BOULDER CREEK

2.4 MI E OF JCT US 287, Boulder, CO

Built 2011 Load: 75.8 t ADT: 14,000

Iris Ave

Good

Over: Elmers Two Mile Ditch

0.15 Mi W of US36/28th St, Boulder, CO

Built 2005 Load: 81.6 t ADT: 21,112

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

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.