US Bridges

Mystic Road over Rapid Ck

Fair

Pennington County, South Dakota · 0.6 Gw 1.9N Mystic · Structure no. 000000052201284

Built
1940
85 years old, rebuilt 1988
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
42 ft
2 main spans
Daily traffic
128
2022 count
Owner
County
County Highway Agency

About this bridge

Mystic Road over Rapid Ck is a steel stringer/multi-beam or girder carrying Mystic Road over Rapid Ck in Pennington County, South Dakota. It was built in 1940 and reconstructed in 1988, 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 5 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 128 vehicles a day, roughly 8% of them trucks, projected to reach 128 by 2033. The structure is 42 ft (12.8 m) long and 19 ft wide. If it were closed, the detour would be 18 mi (29 km).

Location

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CarriesMystic Road
CrossesRapid Ck
Location0.6 Gw 1.9N Mystic
RouteCounty Highway 0
CountyPennington County
StateSouth Dakota
Coordinates44.10586, -103.65291
Functional classRural Major Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no 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 adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating24.1 US tons
Inventory rating14.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckCorrugated steel
Main spans2
Design loadUnknown
Structure length42 ft (12.8 m)
Longest span25 ft (7.6 m)
Deck width19 ft (5.9 m)
Roadway width19 ft (5.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic128 (2022)
Projected traffic128 by 2033
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed18 mi (29 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Mystic Road over Rapid Ck built?

It was built in 1940, making it 85 years old in 2025. It was reconstructed in 1988.

What condition is Mystic Road over Rapid Ck 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 June 2023.

How much traffic does Mystic Road over Rapid Ck carry?

About 128 vehicles per day (2022 count), of which roughly 8% are trucks.

How long is Mystic Road over Rapid Ck?

The structure is 42 ft (12.8 m) long with a longest span of 25 ft (7.6 m) and a deck 19 ft wide.

Who owns Mystic Road over Rapid Ck?

It is owned by the County Highway Agency.