US Bridges

S 205-FRONTAGE RD over Madison River

Fair

Gallatin County, Montana · 1M E Three Forks · Structure no. S00205000+04911

Built
1948
77 years old, rebuilt 2004
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
224 ft
2 main spans
Daily traffic
1,501
2023 count
Owner
State
State Highway Agency

About this bridge

S 205-FRONTAGE RD over Madison River is a steel continuous stringer/multi-beam or girder carrying S 205-FRONTAGE RD over Madison River in Gallatin County, Montana. It was built in 1948 and reconstructed in 2004, so it is 77 years old, older 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 1,501 vehicles a day, roughly 1% of them trucks, projected to reach 1,576 by 2043. The structure is 224 ft (68.2 m) long and 32 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

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CarriesS 205-FRONTAGE RD
CrossesMadison River
Location1M E Three Forks
RouteState Highway 205
CountyGallatin County
StateMontana
Coordinates45.90105, -111.52562
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating20.4 US tons
Inventory rating15.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length224 ft (68.2 m)
Longest span110 ft (33.5 m)
Deck width32 ft (9.8 m)
Roadway width28 ft (8.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,501 (2023)
Projected traffic1,576 by 2043
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 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 S 205-FRONTAGE RD over Madison River built?

It was built in 1948, making it 77 years old in 2025. It was reconstructed in 2004.

What condition is S 205-FRONTAGE RD over Madison River 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 May 2023.

How much traffic does S 205-FRONTAGE RD over Madison River carry?

About 1,501 vehicles per day (2023 count), of which roughly 1% are trucks.

How long is S 205-FRONTAGE RD over Madison River?

The structure is 224 ft (68.2 m) long with a longest span of 110 ft (33.5 m) and a deck 32 ft wide.

Who owns S 205-FRONTAGE RD over Madison River?

It is owned by the State Highway Agency.