US Bridges

State Park RD over Center Lake Inlet

PoorPosted for load

Custer County, South Dakota · 8.4E 2.7N of Custer · Structure no. 000000017314043

Built
1950
75 years old
Condition
Poor
inspected October 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
24 ft
1 main span
Daily traffic
1,000
2022 count
Owner
State
Other State Agency

About this bridge

State Park RD over Center Lake Inlet is a steel stringer/multi-beam or girder carrying State Park RD over Center Lake Inlet in Custer County, South Dakota. It was built in 1950, so it is 75 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 poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 1,000 vehicles a day, roughly 2% of them trucks, projected to reach 1,000 by 2040. The structure is 24 ft (7.4 m) long and 22 ft wide. If it were closed, the detour would be 14.3 mi (23 km).

CarriesState Park RD
CrossesCenter Lake Inlet
Location8.4E 2.7N of Custer
RouteState Lands Road 0
Coordinates43.80566, -103.43077
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating24 US tons
Inventory rating18 US tons

Structure

MaterialSteel
DeckWood or timber
Main spans1
Design loadUnknown
Structure length24 ft (7.4 m)
Longest span24 ft (7.2 m)
Deck width22 ft (6.8 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,000 (2022)
Projected traffic1,000 by 2040
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.3 mi (23 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerOther State Agency
Maintained byOther State Agency
Historic statusEligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$300,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was State Park RD over Center Lake Inlet built?

It was built in 1950, making it 75 years old in 2025.

What condition is State Park RD over Center Lake Inlet in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in October 2024.

How much traffic does State Park RD over Center Lake Inlet carry?

About 1,000 vehicles per day (2022 count), of which roughly 2% are trucks.

How long is State Park RD over Center Lake Inlet?

The structure is 24 ft (7.4 m) long with a longest span of 24 ft (7.2 m) and a deck 22 ft wide.

Who owns State Park RD over Center Lake Inlet?

It is owned by the Other State Agency.