US Bridges

River Road over Salmon Hole Brook

Fair

Grafton County, New Hampshire · 0.3 MI from Nh RTE 117 · Structure no. 015001010011200

Built
1920
105 years old, rebuilt 1980
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
33 ft
1 main span
Daily traffic
161
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

River Road over Salmon Hole Brook is a steel stringer/multi-beam or girder carrying River Road over Salmon Hole Brook in Grafton County, New Hampshire. It was built in 1920 and reconstructed in 1980, so it is 105 years old, older than the New Hampshire average of 56.9 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 161 vehicles a day, projected to reach 238 by 2043. The structure is 33 ft (10.1 m) long and 21 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesRiver Road
CrossesSalmon Hole Brook
Location0.3 MI from Nh RTE 117
CountyGrafton County
StateNew Hampshire
Coordinates44.23758, -71.87578
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating27 US tons
Inventory rating18 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length33 ft (10.1 m)
Longest span22 ft (6.7 m)
Deck width21 ft (6.4 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic161 (2023)
Projected traffic238 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$314,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was River Road over Salmon Hole Brook built?

It was built in 1920, making it 105 years old in 2025. It was reconstructed in 1980.

What condition is River Road over Salmon Hole Brook 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 October 2023.

How much traffic does River Road over Salmon Hole Brook carry?

About 161 vehicles per day (2023 count).

How long is River Road over Salmon Hole Brook?

The structure is 33 ft (10.1 m) long with a longest span of 22 ft (6.7 m) and a deck 21 ft wide.

Who owns River Road over Salmon Hole Brook?

It is owned by the City or Municipal Highway Agency.