US Bridges

Cinnabar Basin RD over Yellowstone River 068

Fair

Park County, Montana · Corwin Springs · Structure no. L34322000+02001

Built
2008
17 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
348 ft
3 main spans
Daily traffic
100
2025 count
Owner
County
County Highway Agency

About this bridge

Cinnabar Basin RD over Yellowstone River 068 is a prestressed concrete stringer/multi-beam or girder carrying Cinnabar Basin RD over Yellowstone River 068 in Park County, Montana. It was built in 2008, so it is 17 years old, younger than the Montana average of 47 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 100 vehicles a day, roughly 3% of them trucks, projected to reach 100 by 2040. The structure is 348 ft (106 m) long and 32 ft wide. If it were closed, the detour would be 8.7 mi (14 km).

Location

Open in Google Maps
CarriesCinnabar Basin RD
CrossesYellowstone River 068
LocationCorwin Springs
RouteCounty Highway 34322
CountyPark County
StateMontana
Coordinates45.11157, -110.79304
Functional classRural Local

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2024
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 geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating71 US tons
Inventory rating45 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length348 ft (106 m)
Longest span123 ft (37.5 m)
Deck width32 ft (9.9 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2025)
Projected traffic100 by 2040
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.7 mi (14 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$380,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Cinnabar Basin RD over Yellowstone River 068 built?

It was built in 2008, making it 17 years old in 2025.

What condition is Cinnabar Basin RD over Yellowstone River 068 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 July 2024.

How much traffic does Cinnabar Basin RD over Yellowstone River 068 carry?

About 100 vehicles per day (2025 count), of which roughly 3% are trucks.

How long is Cinnabar Basin RD over Yellowstone River 068?

The structure is 348 ft (106 m) long with a longest span of 123 ft (37.5 m) and a deck 32 ft wide.

Who owns Cinnabar Basin RD over Yellowstone River 068?

It is owned by the County Highway Agency.