Nd Highway 21 over Cannonball River
GoodSlope County, North Dakota · 3 East JCT US 85 · Structure no. 0021003078
- Built
- 1983
- 42 years old
- Condition
- Good
- inspected June 2023
- Type
- Box Beam or Girders - Single or Spread
- Prestressed Concrete Continuous
- Length
- 105 ft
- 3 main spans
- Daily traffic
- 350
- 2019 count
- Owner
- State
- State Highway Agency
About this bridge
Nd Highway 21 over Cannonball River is a prestressed concrete continuous box beam or girders - single or spread carrying Nd Highway 21 over Cannonball River in Slope County, North Dakota. It was built in 1983, so it is 42 years old, younger than the North Dakota average of 48.2 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 350 vehicles a day, roughly 38% of them trucks, projected to reach 430 by 2039. The structure is 105 ft (32 m) long and 38 ft wide. If it were closed, the detour would be 54.1 mi (87 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Nd Highway 21 over Cannonball River built?
It was built in 1983, making it 42 years old in 2025.
What condition is Nd Highway 21 over Cannonball 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 June 2023.
How much traffic does Nd Highway 21 over Cannonball River carry?
About 350 vehicles per day (2019 count), of which roughly 38% are trucks.
How long is Nd Highway 21 over Cannonball River?
The structure is 105 ft (32 m) long with a longest span of 40 ft (12.2 m) and a deck 38 ft wide.
Who owns Nd Highway 21 over Cannonball River?
It is owned by the State Highway Agency.