US Bridges

Quast LN over Surprise Ditch 060

PoorPosted for load

Ravalli County, Montana · 1M N Corvallis · Structure no. L41316000+06001

Built
1918
107 years old, rebuilt 1970
Condition
Poor
inspected November 2024
Type
Tee Beam
Concrete
Length
28 ft
1 main span
Daily traffic
537
2023 count
Owner
County
County Highway Agency

About this bridge

Quast LN over Surprise Ditch 060 is a concrete tee beam carrying Quast LN over Surprise Ditch 060 in Ravalli County, Montana. It was built in 1918 and reconstructed in 1970, so it is 107 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. Its operating status is: posted for load restriction.

It carries about 537 vehicles a day, roughly 3% of them trucks, projected to reach 575 by 2043. The structure is 28 ft (8.5 m) long and 31 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesQuast LN
CrossesSurprise Ditch 060
Location1M N Corvallis
RouteCounty Highway 41316
CountyRavalli County
StateMontana
Coordinates46.32719, -114.10829
Functional classRural Minor Collector

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.
Superstructure7 GoodSome minor problems.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourScour critical; foundations unstable for calculated scour conditions
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 adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating24.9 US tons
Inventory rating18 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length28 ft (8.5 m)
Longest span26 ft (7.9 m)
Deck width31 ft (9.3 m)
Roadway width30 ft (9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic537 (2023)
Projected traffic575 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Quast LN over Surprise Ditch 060 built?

It was built in 1918, making it 107 years old in 2025. It was reconstructed in 1970.

What condition is Quast LN over Surprise Ditch 060 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 November 2024.

How much traffic does Quast LN over Surprise Ditch 060 carry?

About 537 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Quast LN over Surprise Ditch 060?

The structure is 28 ft (8.5 m) long with a longest span of 26 ft (7.9 m) and a deck 31 ft wide.

Who owns Quast LN over Surprise Ditch 060?

It is owned by the County Highway Agency.