MAIN BOULDER RD
Carrying MAIN BOULDER RD over WEST BOULDER RIVER
MCLEOD, Sweet Grass, Montana
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: MAIN BOULDER RD
The MAIN BOULDER RD bridge in Sweet Grass, Montana carries MAIN BOULDER RD over WEST BOULDER RIVER. It was built in 1976, making it 50 years old today. The structure is built primarily of prestressed concrete and spans 3 sections, stretching 46.6 meters (153 feet) end to end. Daily traffic averages 526 vehicles, placing it in the lower-traffic tier of Montana bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 6/9, superstructure at 7/9, substructure at 7/9. The weakest component sits in fair condition. None of this bridge's reported major components fall into the Poor condition range. Its NBI inventory load rating is 23.6 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How MAIN BOULDER RD compares
Live comparison across Montana.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1976
- Material
- Prestressed Concrete
- Number of Spans
- 3
- Structure Length
- 46.6 m (153 ft)
- Deck Width
- 10.5 m (34 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 526 vehicles/day
- Structure Number
- S00298016+03261
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
- • The superstructure (beams and supports above the deck) rates good at 7/9, with no significant deterioration on file.
- • The substructure (piers and abutments) is in good condition (7/9), showing no significant deterioration.
How to read this record
This page shows what the last federal inspection recorded, not whether MAIN BOULDER RD is safe to cross today. Here is how to use it.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Learn how the 0–9 condition scale and Good/Fair/Poor categories are defined. How condition ratings work
- Compare MAIN BOULDER RD against other structures in Sweet Grass and across Montana. Montana bridges
- Noticed visible damage or a safety concern? Report it to the agency that owns the bridge, or call 911 in an emergency. How to report a bridge
Condition codes come straight from the FHWA National Bridge Inventory and are not a real-time safety judgment. Only the owning agency, a state DOT, county, or other owner, can post, restrict, or close a bridge.
Frequently Asked Questions
What do the condition ratings mean for MAIN BOULDER RD?
MAIN BOULDER RD in Sweet Grass, Montana has a deck rating of 6/9, superstructure rating of 7/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is MAIN BOULDER RD inspected?
MAIN BOULDER RD's responsible agency sets its routine interval under FHWA's risk-based inspection rules; this page does not expose the scheduled interval. It carries about 526 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. MAIN BOULDER RD is currently shown as Fair condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for MAIN BOULDER RD?
MAIN BOULDER RD has an NBI inventory load rating of 23.6 metric tons.
Who is responsible for maintaining MAIN BOULDER RD?
MAIN BOULDER RD is owned and maintained by State Highway Agency.
How old is MAIN BOULDER RD and does age affect safety?
MAIN BOULDER RD was built in 1976, making it 50 years old.
Disclaimer: Bridge condition data is from the FHWA NBI and reflects the last reported inspection. A Poor condition rating is not a live declaration that a bridge is closed or unsafe for travel. For current closure, posting, or safety information, contact the responsible transportation agency.
Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.