FHWA NBI 2024 Inspection record Public-domain dataset

S 324

Carrying S 324 over CLARK CANYON DAM SPLWY

CLARK CANYON DAM, Beaverhead, Montana

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Fair
22 t Inventory load rating

Bridge Snapshot: S 324

The S 324 bridge in Beaverhead, Montana carries S 324 over CLARK CANYON DAM SPLWY. It was built in 1962, making it 64 years old today. The structure is built primarily of concrete and spans 2 sections, stretching 22.1 meters (73 feet) end to end. Daily traffic averages 389 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 5/9. 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 21.8 metric tons.

Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.

How S 324 compares

▼ 8.9
Load rating vs Montana average (30.7 t)
Bottom 19%
Lower load rating than 81% of Montana bridges
217
Bridges in Beaverhead · 20 in Poor condition
S 324 21.8 t
Montana average 30.7 t

Live comparison across Montana.

Historical Sufficiency Rating

PlainBridge-computed
75.1 / 100 - historical 50–79.9 band
Structural adequacy /55
33.8
Serviceability /30
29.0
Essentiality /15
14.4
Special reductions
−2.0

FHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.

Condition Ratings

Deck
6/9
Fair (5–6)
Superstructure
7/9
Good (7–9)
Substructure
5/9
Fair (5–6)
Inventory Load Rating
21.8 t
NBI inventory level (metric tons)
Overall Condition
Fair

Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.

Structural Details

Year Built
1962
Material
Concrete
Number of Spans
2
Structure Length
22.1 m (73 ft)
Deck Width
10.2 m (33 ft)
Owner
State Highway Agency
Avg Daily Traffic
389 vehicles/day
Structure Number
S00324001+00001

Condition Analysis

  • At 6/9, the deck (driving surface) shows fair condition, with minor wear flagged for upkeep.
  • The superstructure (beams and supports above the deck) rates good at 7/9, with no significant deterioration on file.
  • The substructure (piers and abutments) rates fair at 5/9, minor deterioration that routine maintenance should address.

How to read this record

This page shows what the last federal inspection recorded, not whether S 324 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 S 324 against other structures in Beaverhead 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 S 324?

S 324 in Beaverhead, Montana has a deck rating of 6/9, superstructure rating of 7/9, and substructure rating of 5/9 on the FHWA's 0–9 scale.

How often is S 324 inspected?

S 324'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 389 vehicles per day.

What does “structurally deficient” mean in older bridge reports?

FHWA retired that reported status beginning with the 2018 archive. S 324 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 S 324?

S 324 has an NBI inventory load rating of 21.8 metric tons.

Who is responsible for maintaining S 324?

S 324 is owned and maintained by State Highway Agency.

How old is S 324 and does age affect safety?

S 324 was built in 1962, making it 64 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.

Data sourced from the Federal Highway Administration National Bridge Inventory. See our methodology for details. Retrieved and formatted by PlainBridges

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.