US Bridges

Bobtail Road over Bobtail Creek

Fair

Gilpin County, Colorado · S of Mardi Gras Casino · Structure no. BLKHWK-BOBTAIL

Built
1999
26 years old
Condition
Fair
inspected April 2023
Type
Arch - Thru
Steel
Length
124 ft
1 main span
Daily traffic
698
2020 count
Owner
City
City or Municipal Highway Agency

About this bridge

Bobtail Road over Bobtail Creek is a steel arch - thru carrying Bobtail Road over Bobtail Creek in Gilpin County, Colorado. It was built in 1999, so it is 26 years old, younger than the Colorado average of 42.2 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 698 vehicles a day, roughly 50% of them trucks, projected to reach 838 by 2040. The structure is 124 ft (37.9 m) long and 26 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesBobtail Road
CrossesBobtail Creek
LocationS of Mardi Gras Casino
RouteCity Street 0
CountyGilpin County
StateColorado
Coordinates39.79828, -105.48935
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations on dry land well above flood water elevations
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.7 US tons
Inventory rating28 US tons

Structure

Structure typeArch - Thru
MaterialSteel
DeckCorrugated steel
Main spans1 (+2 approach)
Design loadHS 20
Structure length124 ft (37.9 m)
Longest span108 ft (32.8 m)
Deck width26 ft (8 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deck18 ft (5.5 m)

Traffic and service

Average daily traffic698 (2020)
Projected traffic838 by 2040
Trucks50%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Bobtail Road over Bobtail Creek built?

It was built in 1999, making it 26 years old in 2025.

What condition is Bobtail Road over Bobtail Creek in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in April 2023.

How much traffic does Bobtail Road over Bobtail Creek carry?

About 698 vehicles per day (2020 count), of which roughly 50% are trucks.

How long is Bobtail Road over Bobtail Creek?

The structure is 124 ft (37.9 m) long with a longest span of 108 ft (32.8 m) and a deck 26 ft wide.

Who owns Bobtail Road over Bobtail Creek?

It is owned by the City or Municipal Highway Agency.