US Bridges

S 19th RD over Hyalite Creek

Fair

Gallatin County, Montana · 6M SW Bozeman · Structure no. S00345006+01001

Built
1988
37 years old, rebuilt 2020
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
32 ft
1 main span
Daily traffic
1,856
2023 count
Owner
County
County Highway Agency

About this bridge

S 19th RD over Hyalite Creek is a steel stringer/multi-beam or girder carrying S 19th RD over Hyalite Creek in Gallatin County, Montana. It was built in 1988 and reconstructed in 2020, so it is 37 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 1,856 vehicles a day, roughly 2% of them trucks, projected to reach 1,995 by 2043. The structure is 32 ft (9.8 m) long and 26 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

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CarriesS 19th RD
CrossesHyalite Creek
Location6M SW Bozeman
RouteCounty Highway 345
CountyGallatin County
StateMontana
Coordinates45.59067, -111.08806
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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating42 US tons
Inventory rating33 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckCorrugated steel
Main spans1
Design loadUnknown
Structure length32 ft (9.8 m)
Longest span31 ft (9.4 m)
Deck width26 ft (7.9 m)
Roadway width25 ft (7.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,856 (2023)
Projected traffic1,995 by 2043
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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$78,000
NavigationNo navigation control on waterway

Frequently asked questions

When was S 19th RD over Hyalite Creek built?

It was built in 1988, making it 37 years old in 2025. It was reconstructed in 2020.

What condition is S 19th RD over Hyalite 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 April 2023.

How much traffic does S 19th RD over Hyalite Creek carry?

About 1,856 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is S 19th RD over Hyalite Creek?

The structure is 32 ft (9.8 m) long with a longest span of 31 ft (9.4 m) and a deck 26 ft wide.

Who owns S 19th RD over Hyalite Creek?

It is owned by the County Highway Agency.