US Bridges

SH 75 over Redfish Lake Creek

Fair

Custer County, Idaho · 5.6 S. Stanley · Structure no. 000000000017765

Built
1960
65 years old
Condition
Fair
inspected July 2024
Type
Tee Beam
Concrete Continuous
Length
130 ft
3 main spans
Daily traffic
1,100
2023 count
Owner
State
State Highway Agency

About this bridge

SH 75 over Redfish Lake Creek is a concrete continuous tee beam carrying SH 75 over Redfish Lake Creek in Custer County, Idaho. It was built in 1960, so it is 65 years old, older than the Idaho average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 1,100 vehicles a day, roughly 21% of them trucks, projected to reach 1,650 by 2042. The structure is 130 ft (39.6 m) long and 32 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesSH 75
CrossesRedfish Lake Creek
Location5.6 S. Stanley
RouteState Highway 75
CountyCuster County
StateIdaho
Coordinates44.16839, -114.89953
Functional classRural Minor Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating60 US tons
Inventory rating35.1 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length130 ft (39.6 m)
Longest span50 ft (15.2 m)
Deck width32 ft (9.8 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,100 (2023)
Projected traffic1,650 by 2042
Trucks21%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1.3 million (2020 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SH 75 over Redfish Lake Creek built?

It was built in 1960, making it 65 years old in 2025.

What condition is SH 75 over Redfish Lake 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 July 2024.

How much traffic does SH 75 over Redfish Lake Creek carry?

About 1,100 vehicles per day (2023 count), of which roughly 21% are trucks.

How long is SH 75 over Redfish Lake Creek?

The structure is 130 ft (39.6 m) long with a longest span of 50 ft (15.2 m) and a deck 32 ft wide.

Who owns SH 75 over Redfish Lake Creek?

It is owned by the State Highway Agency.