US Bridges

Sd Route 87 over Sd Route 87

Fair

Custer County, South Dakota · On Sd Route 87 MP 43.1; · Structure no. 1560003P0000000

Built
1940
85 years old, rebuilt 2007
Condition
Fair
inspected January 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
77 ft
3 main spans
Daily traffic
326
2022 count
Owner
Federal
National Park Service

About this bridge

Sd Route 87 over Sd Route 87 is a steel stringer/multi-beam or girder carrying Sd Route 87 over Sd Route 87 in Custer County, South Dakota. It was built in 1940 and reconstructed in 2007, so it is 85 years old, older than the South Dakota average of 48.9 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 326 vehicles a day, roughly 2% of them trucks, projected to reach 391 by 2042. The structure is 77 ft (23.5 m) long and 22 ft wide. If it were closed, the detour would be 41 mi (66 km).

Location

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CarriesSd Route 87
CrossesSd Route 87
LocationOn Sd Route 87 MP 43.1;
RouteFederal Lands Road 31087
CountyCuster County
StateSouth Dakota
Coordinates43.60131, -103.49428
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating51 US tons
Inventory rating30 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckWood or timber
Main spans3
Design loadHS 20
Structure length77 ft (23.5 m)
Longest span41 ft (12.5 m)
Deck width22 ft (6.6 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic326 (2022)
Projected traffic391 by 2042
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed41 mi (66 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerNational Park Service
Maintained byNational Park Service
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Sd Route 87 over Sd Route 87 built?

It was built in 1940, making it 85 years old in 2025. It was reconstructed in 2007.

What condition is Sd Route 87 over Sd Route 87 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 January 2024.

How much traffic does Sd Route 87 over Sd Route 87 carry?

About 326 vehicles per day (2022 count), of which roughly 2% are trucks.

How long is Sd Route 87 over Sd Route 87?

The structure is 77 ft (23.5 m) long with a longest span of 41 ft (12.5 m) and a deck 22 ft wide.

Who owns Sd Route 87 over Sd Route 87?

It is owned by the National Park Service.