OLD HWY 87
Carrying OLD HWY 87 over TWO LEGGINS CANAL 0
1M W HARDIN, Big Horn, Montana
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
OLD HWY 87 in Big Horn, Montana sits above 15% of rated Montana bridges on inventory load rating (21 t), while its 1931 build year is earlier than 99% of Big Horn's recorded-year cohort (135 bridges).
OLD HWY 87 in Big Horn, Montana is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1931, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 4. The lowest applicable rating sets the federal condition category, so this Poor result describes the weakest reported component rather than the structure as a whole. No NBI category is a closure decision or a live crossing-safety verdict.
NBI record plate
Structure MT:L02313021+06001
PRE-1950 · CONCRETE · SINGLE-SPAN · SUB-LED · LOCAL-ADT · STANDARD-LOAD · CAT-POOR
- PRE-1950 Pre-1950
- CONCRETE Concrete
- SINGLE-SPAN Single span
- SUB-LED Substructure-led
- LOCAL-ADT Local ADT
- STANDARD-LOAD Standard load
- CAT-POOR Poor
Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.
Bridge Snapshot: OLD HWY 87
The OLD HWY 87 bridge in Big Horn, Montana carries OLD HWY 87 over TWO LEGGINS CANAL 0. It was built in 1931, making it 95 years old today. The structure is built primarily of concrete and spans 1 section, stretching 10.1 meters (33 feet) end to end. Daily traffic averages 561 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 6/9, substructure at 4/9. The weakest component sits in poor condition. A component scored 4 or below, placing this bridge in the federal Poor condition category rather than declaring it unsafe or closed.
How OLD HWY 87 compares
Age against the county: built in 1931, earlier than 133 of Big Horn's 135 bridges with a recorded construction year (99%), against a county median build year of 1980. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Montana bridges with a recorded inventory load rating (5,144 of 5,224 rated).
OLD HWY 87 vs every rated Montana bridge
Inventory load rating (metric tons), FHWA NBI, this state
21 Top 85% higher than 15% of 5,144 bridges
rated Montana bridges, bucketed by value
Each bar is a band; taller bars hold more bridges. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source FHWA National Bridge Inventory · August 2026
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Reported 0–9 component ratings from the FHWA NBI. The highlighted component is the lowest reported input to this record’s current condition category; it is not a closure or live crossing-safety decision.
Big Horn inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 135 bridges in this county. Orthogonal to this structure's component profile above: a county catalog share, not a live crossing-safety verdict.
Structural Details
- Year Built
- 1931
- Material
- Concrete
- Number of Spans
- 1
- Structure Length
- 10.1 m (33 ft)
- Deck Width
- 7.7 m (25 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 561 vehicles/day
- Structure Number
- L02313021+06001
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 fair at 6/9, minor deterioration that routine maintenance should address.
- • The substructure (piers and abutments) rates poor at 4/9, with advanced deterioration recorded on the latest inspection.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
OLD HWY 87 is in the federal Poor condition category. That is a component-based result, not a closure order.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Understand what Poor condition does and does not mean before drawing conclusions. Poor condition explained
- Compare OLD HWY 87 against other structures in Big Horn 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 OLD HWY 87?
OLD HWY 87 in Big Horn, Montana has a deck rating of 6/9, superstructure rating of 6/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.
How often is OLD HWY 87 inspected?
OLD HWY 87'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 561 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. OLD HWY 87 is currently shown as Poor condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for OLD HWY 87?
OLD HWY 87 has an NBI inventory load rating of 20.9 metric tons.
Who is responsible for maintaining OLD HWY 87?
OLD HWY 87 is owned and maintained by State Highway Agency.
How old is OLD HWY 87 and does age affect safety?
OLD HWY 87 was built in 1931, making it 95 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.
Share this inspection record
Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Component ratings, ADT, and condition category on this page are copied from the NBI record for this structure; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.