US Bridges

N3550 over Grayhorse Creek Trib.

Fair

Osage County, Oklahoma · .25N of HWY 20 · Structure no. 297970000000000

Built
2009
16 years old
Condition
Fair
inspected March 2024
Type
Culvert
Concrete
Length
25 ft
2 main spans
Daily traffic
250
2022 count
Owner
County
County Highway Agency

About this bridge

N3550 over Grayhorse Creek Trib. is a concrete culvert carrying N3550 over Grayhorse Creek Trib. in Osage County, Oklahoma. It was built in 2009, so it is 16 years old, younger than the Oklahoma average of 47.8 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 250 vehicles a day, roughly 10% of them trucks, projected to reach 400 by 2042. The structure is 25 ft (7.6 m) long. If it were closed, the detour would be 13 mi (21 km).

Location

Open in Google Maps
CarriesN3550
CrossesGrayhorse Creek Trib.
Location.25N of HWY 20
RouteCounty Highway N3550
CountyOsage County
StateOklahoma
Coordinates36.50361, -96.675
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Channel and channel protection8 Very GoodNo problems noted.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating110.1 US tons
Inventory rating99.5 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans2
Design loadHS 20
Structure length25 ft (7.6 m)
Longest span12 ft (3.7 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic250 (2022)
Projected traffic400 by 2042
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed13 mi (21 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$299,000
NavigationNo navigation control on waterway

Frequently asked questions

When was N3550 over Grayhorse Creek Trib. built?

It was built in 2009, making it 16 years old in 2025.

What condition is N3550 over Grayhorse Creek Trib. 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 2024.

How much traffic does N3550 over Grayhorse Creek Trib. carry?

About 250 vehicles per day (2022 count), of which roughly 10% are trucks.

How long is N3550 over Grayhorse Creek Trib.?

The structure is 25 ft (7.6 m) long with a longest span of 12 ft (3.7 m).

Who owns N3550 over Grayhorse Creek Trib.?

It is owned by the County Highway Agency.