US Bridges

County RD 597 over Oyster CR

PoorPosted for load

Lewis County, Missouri · S 6 T 60 N R 5 W · Structure no. 20999

Built
1910
115 years old
Condition
Poor
inspected February 2025
Type
Truss - Thru
Steel
Length
47 ft
1 main span
Daily traffic
15
2024 count
Owner
County
County Highway Agency

About this bridge

County RD 597 over Oyster CR is a steel truss - thru carrying County RD 597 over Oyster CR in Lewis County, Missouri. It was built in 1910, so it is 115 years old, older than the Missouri average of 45.1 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 3 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 15 vehicles a day, roughly 10% of them trucks, projected to reach 19 by 2044. The structure is 47 ft (14.3 m) long and 18 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesCounty RD 597
CrossesOyster CR
LocationS 6 T 60 N R 5 W
RouteCounty Highway 284
CountyLewis County
StateMissouri
Coordinates40.02475, -91.49339
Functional classRural Local

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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
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 inspectionFebruary 2025
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating20.8 US tons
Inventory rating11.9 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length47 ft (14.3 m)
Longest span45 ft (13.7 m)
Deck width18 ft (5.5 m)
Roadway width18 ft (5.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic15 (2024)
Projected traffic19 by 2044
Trucks10%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$383,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was County RD 597 over Oyster CR built?

It was built in 1910, making it 115 years old in 2025.

What condition is County RD 597 over Oyster CR 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 February 2025.

How much traffic does County RD 597 over Oyster CR carry?

About 15 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is County RD 597 over Oyster CR?

The structure is 47 ft (14.3 m) long with a longest span of 45 ft (13.7 m) and a deck 18 ft wide.

Who owns County RD 597 over Oyster CR?

It is owned by the County Highway Agency.