US Bridges

SH 21 over Mores Cr;n.Y. Gulch #2

Fair

Boise County, Idaho · 3.8 S. Idaho City · Structure no. 000000000012876

Built
2002
23 years old
Condition
Fair
inspected October 2022
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
92 ft
1 main span
Daily traffic
2,000
2023 count
Owner
State
State Highway Agency

About this bridge

SH 21 over Mores Cr;n.Y. Gulch #2 is a prestressed concrete stringer/multi-beam or girder carrying SH 21 over Mores Cr;n.Y. Gulch #2 in Boise County, Idaho. It was built in 2002, so it is 23 years old, younger 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 2,000 vehicles a day, roughly 18% of them trucks, projected to reach 3,000 by 2042. The structure is 92 ft (28 m) long and 40 ft wide. If it were closed, the detour would be 75.2 mi (121 km).

Location

Open in Google Maps
CarriesSH 21
CrossesMores Cr;n.Y. Gulch #2
Location3.8 S. Idaho City
RouteState Highway 21
CountyBoise County
StateIdaho
Coordinates43.79303, -115.87886
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating97 US tons
Inventory rating55 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length92 ft (28 m)
Longest span89 ft (27.1 m)
Deck width40 ft (12.2 m)
Roadway width37 ft (11.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,000 (2023)
Projected traffic3,000 by 2042
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed75.2 mi (121 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was SH 21 over Mores Cr;n.Y. Gulch #2 built?

It was built in 2002, making it 23 years old in 2025.

What condition is SH 21 over Mores Cr;n.Y. Gulch #2 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 October 2022.

How much traffic does SH 21 over Mores Cr;n.Y. Gulch #2 carry?

About 2,000 vehicles per day (2023 count), of which roughly 18% are trucks.

How long is SH 21 over Mores Cr;n.Y. Gulch #2?

The structure is 92 ft (28 m) long with a longest span of 89 ft (27.1 m) and a deck 40 ft wide.

Who owns SH 21 over Mores Cr;n.Y. Gulch #2?

It is owned by the State Highway Agency.