US Bridges

Cantwell Road over Jack River

Fair

Denali Borough, Alaska · Mile Point 0.7 · Structure no. 0281

Built
1977
48 years old
Condition
Fair
inspected June 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
180 ft
3 main spans
Daily traffic
390
2020 count
Owner
State
State Highway Agency

About this bridge

Cantwell Road over Jack River is a wood or timber stringer/multi-beam or girder carrying Cantwell Road over Jack River in Denali Borough, Alaska. It was built in 1977, so it is 48 years old, older than the Alaska average of 35.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 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 390 vehicles a day, roughly 23% of them trucks, projected to reach 1,340 by 2039. The structure is 180 ft (54.9 m) long and 25 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesCantwell Road
CrossesJack River
LocationMile Point 0.7
RouteState Highway NSP00
CountyDenali Borough
StateAlaska
Coordinates63.39419, -148.92237
Functional classRural Major Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50.3 US tons
Inventory rating34.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans3
Design loadHS 20
Structure length180 ft (54.9 m)
Longest span68 ft (20.7 m)
Deck width25 ft (7.6 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic390 (2020)
Projected traffic1,340 by 2039
Trucks23%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 Cantwell Road over Jack River built?

It was built in 1977, making it 48 years old in 2025.

What condition is Cantwell Road over Jack 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 June 2024.

How much traffic does Cantwell Road over Jack River carry?

About 390 vehicles per day (2020 count), of which roughly 23% are trucks.

How long is Cantwell Road over Jack River?

The structure is 180 ft (54.9 m) long with a longest span of 68 ft (20.7 m) and a deck 25 ft wide.

Who owns Cantwell Road over Jack River?

It is owned by the State Highway Agency.