US Bridges

S 24 over Nelson Creek

Fair

McCone County, Montana · 15M N Flowing Wells · Structure no. P00042014+06981

Built
1963
62 years old
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
134 ft
3 main spans
Daily traffic
153
2023 count
Owner
State
State Highway Agency

About this bridge

S 24 over Nelson Creek is a prestressed concrete stringer/multi-beam or girder carrying S 24 over Nelson Creek in McCone County, Montana. It was built in 1963, so it is 62 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 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 153 vehicles a day, roughly 4% of them trucks, projected to reach 161 by 2043. The structure is 134 ft (40.9 m) long and 31 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

CarriesS 24
CrossesNelson Creek
Location15M N Flowing Wells
RouteState Highway 24
StateMontana
Coordinates47.53661, -106.1535
Functional classRural Minor Arterial

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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2023
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 adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating44 US tons
Inventory rating34 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length134 ft (40.9 m)
Longest span52 ft (15.8 m)
Deck width31 ft (9.4 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic153 (2023)
Projected traffic161 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 24 over Nelson Creek built?

It was built in 1963, making it 62 years old in 2025.

What condition is S 24 over Nelson 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 March 2023.

How much traffic does S 24 over Nelson Creek carry?

About 153 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is S 24 over Nelson Creek?

The structure is 134 ft (40.9 m) long with a longest span of 52 ft (15.8 m) and a deck 31 ft wide.

Who owns S 24 over Nelson Creek?

It is owned by the State Highway Agency.