US Bridges

S 7 over Drainage

Poor

Carter County, Montana · 1M NE Ekalaka · Structure no. P00027001+02901

Built
1940
85 years old
Condition
Poor
inspected September 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
39 ft
2 main spans
Daily traffic
473
2023 count
Owner
State
State Highway Agency

About this bridge

S 7 over Drainage is a wood or timber stringer/multi-beam or girder carrying S 7 over Drainage in Carter County, Montana. It was built in 1940, so it is 85 years old, older than the Montana average of 47 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 473 vehicles a day, roughly 9% of them trucks, projected to reach 497 by 2043. The structure is 39 ft (12 m) long and 26 ft wide. If it were closed, the detour would be 23 mi (37 km).

Location

Open in Google Maps
CarriesS 7
CrossesDrainage
Location1M NE Ekalaka
RouteState Highway 7
CountyCarter County
StateMontana
Coordinates45.9099, -104.53547
Functional classRural Minor Arterial

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2024
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 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 rating47 US tons
Inventory rating31 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans2
Design loadH 15
Structure length39 ft (12 m)
Longest span19 ft (5.8 m)
Deck width26 ft (7.9 m)
Roadway width23 ft (6.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic473 (2023)
Projected traffic497 by 2043
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed23 mi (37 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 7 over Drainage built?

It was built in 1940, making it 85 years old in 2025.

What condition is S 7 over Drainage in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in September 2024.

How much traffic does S 7 over Drainage carry?

About 473 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is S 7 over Drainage?

The structure is 39 ft (12 m) long with a longest span of 19 ft (5.8 m) and a deck 26 ft wide.

Who owns S 7 over Drainage?

It is owned by the State Highway Agency.