US Bridges

Rattlesnake CR RD over Rattlesnake Creek

Fair

Missoula County, Montana · Rattlesnake CR · Structure no. 011603000000188

Built
1981
44 years old
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
37 ft
1 main span
Daily traffic
50
Owner
Federal
U.S. Forest Service

About this bridge

Rattlesnake CR RD over Rattlesnake Creek is a prestressed concrete stringer/multi-beam or girder carrying Rattlesnake CR RD over Rattlesnake Creek in Missoula County, Montana. It was built in 1981, so it is 44 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 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 50 vehicles a day, projected to reach 75 by 2045. The structure is 37 ft (11.2 m) long and 12 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

CarriesRattlesnake CR RD
CrossesRattlesnake Creek
LocationRattlesnake CR
RouteFederal Lands Road 99
StateMontana
Coordinates46.96802, -113.8613
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating40.7 US tons
Inventory rating31.4 US tons

Structure

MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 20
Structure length37 ft (11.2 m)
Longest span35 ft (10.8 m)
Deck width12 ft (3.7 m)
Roadway width11 ft (3.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (—)
Projected traffic75 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.2 mi (158 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—
NavigationNo navigation control on waterway

Frequently asked questions

When was Rattlesnake CR RD over Rattlesnake Creek built?

It was built in 1981, making it 44 years old in 2025.

What condition is Rattlesnake CR RD over Rattlesnake Creek 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 November 2024.

How much traffic does Rattlesnake CR RD over Rattlesnake Creek carry?

About 50 vehicles per day (latest count).

How long is Rattlesnake CR RD over Rattlesnake Creek?

The structure is 37 ft (11.2 m) long with a longest span of 35 ft (10.8 m) and a deck 12 ft wide.

Who owns Rattlesnake CR RD over Rattlesnake Creek?

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