US Bridges

Tampico RD over Antelope Creek

Fair

Valley County, Montana · 5M SE Tampico · Structure no. S00246006+07001

Built
1980
45 years old
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
96 ft
3 main spans
Daily traffic
183
2023 count
Owner
State
State Highway Agency

About this bridge

Tampico RD over Antelope Creek is a steel continuous stringer/multi-beam or girder carrying Tampico RD over Antelope Creek in Valley County, Montana. It was built in 1980, so it is 45 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 183 vehicles a day, roughly 6% of them trucks, projected to reach 192 by 2043. The structure is 96 ft (29.3 m) long and 32 ft wide. If it were closed, the detour would be 42.3 mi (68 km).

Location

Open in Google Maps
CarriesTampico RD
CrossesAntelope Creek
Location5M SE Tampico
RouteState Highway 246
CountyValley County
StateMontana
Coordinates48.25, -106.75444
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.4 US tons
Inventory rating35.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length96 ft (29.3 m)
Longest span67 ft (20.4 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic183 (2023)
Projected traffic192 by 2043
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed42.3 mi (68 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 Tampico RD over Antelope Creek built?

It was built in 1980, making it 45 years old in 2025.

What condition is Tampico RD over Antelope 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 Tampico RD over Antelope Creek carry?

About 183 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is Tampico RD over Antelope Creek?

The structure is 96 ft (29.3 m) long with a longest span of 67 ft (20.4 m) and a deck 32 ft wide.

Who owns Tampico RD over Antelope Creek?

It is owned by the State Highway Agency.