US Bridges

Diamond Pond Road over Mohawk River

Fair

Coos County, New Hampshire · 0.14 MI NE JCT Nh 26 · Structure no. 005001720007200

Built
1929
96 years old
Condition
Fair
inspected April 2024
Type
Arch - Deck
Concrete
Length
70 ft
1 main span
Daily traffic
438
2023 count
Owner
State
State Highway Agency

About this bridge

Diamond Pond Road over Mohawk River is a concrete arch - deck carrying Diamond Pond Road over Mohawk River in Coos County, New Hampshire. It was built in 1929, so it is 96 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 438 vehicles a day, roughly 10% of them trucks, projected to reach 648 by 2043. The structure is 70 ft (21.3 m) long and 26 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesDiamond Pond Road
CrossesMohawk River
Location0.14 MI NE JCT Nh 26
RouteState Highway 0
CountyCoos County
StateNew Hampshire
Coordinates44.87668, -71.37127
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.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating27 US tons
Inventory rating16 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans1
Design loadUnknown
Structure length70 ft (21.3 m)
Longest span70 ft (21.3 m)
Deck width26 ft (8 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic438 (2023)
Projected traffic648 by 2043
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 Diamond Pond Road over Mohawk River built?

It was built in 1929, making it 96 years old in 2025.

What condition is Diamond Pond Road over Mohawk River 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 April 2024.

How much traffic does Diamond Pond Road over Mohawk River carry?

About 438 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is Diamond Pond Road over Mohawk River?

The structure is 70 ft (21.3 m) long with a longest span of 70 ft (21.3 m) and a deck 26 ft wide.

Who owns Diamond Pond Road over Mohawk River?

It is owned by the State Highway Agency.