US Bridges

Horse Cr. (T-361) over Slate CR at Dam

Good

Pennington County, South Dakota · T 1 N R 4 E Sec 15 · Structure no. 020306000010030

Built
1935
90 years old
Condition
Good
inspected April 2023
Type
Slab
Concrete
Length
34 ft
2 main spans
Daily traffic
50
1991 count
Owner
Federal
U.S. Forest Service

About this bridge

Horse Cr. (T-361) over Slate CR at Dam is a concrete slab carrying Horse Cr. (T-361) over Slate CR at Dam in Pennington County, South Dakota. It was built in 1935, so it is 90 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 good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 50 vehicles a day, projected to reach 75 by 2045. The structure is 34 ft (10.4 m) long and 15 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesHorse Cr. (T-361)
CrossesSlate CR at Dam
LocationT 1 N R 4 E Sec 15
RouteFederal Lands Road 530
CountyPennington County
StateSouth Dakota
Coordinates44.03886, -103.62499
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating46.4 US tons
Inventory rating35.7 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans2
Design loadH 15
Structure length34 ft (10.4 m)
Longest span16 ft (4.9 m)
Deck width15 ft (4.7 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (1991)
Projected traffic75 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerU.S. Forest Service
Maintained byU.S. Forest Service
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Horse Cr. (T-361) over Slate CR at Dam built?

It was built in 1935, making it 90 years old in 2025.

What condition is Horse Cr. (T-361) over Slate CR at Dam in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in April 2023.

How much traffic does Horse Cr. (T-361) over Slate CR at Dam carry?

About 50 vehicles per day (1991 count).

How long is Horse Cr. (T-361) over Slate CR at Dam?

The structure is 34 ft (10.4 m) long with a longest span of 16 ft (4.9 m) and a deck 15 ft wide.

Who owns Horse Cr. (T-361) over Slate CR at Dam?

It is owned by the U.S. Forest Service.