Mammoth RD over Big Rvr Ovrfl
FairJefferson County, Missouri · S 10 T 39 N R 3 E · Structure no. 21256
- Built
- 1984
- 41 years old
- Condition
- Fair
- inspected February 2025
- Type
- Box Beam or Girders - Multiple
- Prestressed Concrete
- Length
- 64 ft
- 1 main span
- Daily traffic
- 200
- 2023 count
- Owner
- County
- County Highway Agency
About this bridge
Mammoth RD over Big Rvr Ovrfl is a prestressed concrete box beam or girders - multiple carrying Mammoth RD over Big Rvr Ovrfl in Jefferson County, Missouri. It was built in 1984, so it is 41 years old, younger than the Missouri average of 45.1 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 200 vehicles a day, roughly 2% of them trucks, projected to reach 400 by 2043. The structure is 64 ft (19.5 m) long and 28 ft wide. If it were closed, the detour would be 6.2 mi (10 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| 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 Mammoth RD over Big Rvr Ovrfl built?
It was built in 1984, making it 41 years old in 2025.
What condition is Mammoth RD over Big Rvr Ovrfl 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 February 2025.
How much traffic does Mammoth RD over Big Rvr Ovrfl carry?
About 200 vehicles per day (2023 count), of which roughly 2% are trucks.
How long is Mammoth RD over Big Rvr Ovrfl?
The structure is 64 ft (19.5 m) long with a longest span of 63 ft (19.2 m) and a deck 28 ft wide.
Who owns Mammoth RD over Big Rvr Ovrfl?
It is owned by the County Highway Agency.