US Bridges

SR-121 over Stillwater River

Good

Darke County, Ohio · 1.42MI.S. of Jct. SR-242 · Structure no. 1902172

Built
2007
18 years old
Condition
Good
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
172 ft
3 main spans
Daily traffic
2,740
2015 count
Owner
State
State Highway Agency

About this bridge

SR-121 over Stillwater River is a steel continuous stringer/multi-beam or girder carrying SR-121 over Stillwater River in Darke County, Ohio. It was built in 2007, so it is 18 years old, younger than the Ohio average of 47.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 2,740 vehicles a day, roughly 4% of them trucks, projected to reach 3,803 by 2035. The structure is 172 ft (52.4 m) long and 43 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesSR-121
CrossesStillwater River
Location1.42MI.S. of Jct. SR-242
RouteState Highway 121
CountyDarke County
StateOhio
Coordinates40.19085, -84.52365
Functional classRural Major Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure9 ExcellentNo problems noted.
Substructure9 ExcellentNo problems noted.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation9: Superior to present desirable criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53.9 US tons
Inventory rating41.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 25 or greater
Structure length172 ft (52.4 m)
Longest span70 ft (21.3 m)
Deck width43 ft (13.1 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,740 (2015)
Projected traffic3,803 by 2035
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 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 SR-121 over Stillwater River built?

It was built in 2007, making it 18 years old in 2025.

What condition is SR-121 over Stillwater River in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in July 2023.

How much traffic does SR-121 over Stillwater River carry?

About 2,740 vehicles per day (2015 count), of which roughly 4% are trucks.

How long is SR-121 over Stillwater River?

The structure is 172 ft (52.4 m) long with a longest span of 70 ft (21.3 m) and a deck 43 ft wide.

Who owns SR-121 over Stillwater River?

It is owned by the State Highway Agency.