IRR BIA RTE 13
Carrying IRR BIA RTE 13 over SOUTH FORK MILK RIVER
31KM NORTH BLACKFEET SCHL, Glacier, Montana
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
IRR BIA RTE 13 in Glacier, Montana sits above 2% of rated Montana bridges on inventory load rating (7 t), while its 1979 build year is earlier than 44% of Glacier's recorded-year cohort (71 bridges).
IRR BIA RTE 13 in Glacier, Montana is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1979, 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:00000000000C130
INTERSTATE-ERA · TIMBER · LONG-SPAN-RUN · SUB-LED · LOCAL-ADT · LIGHT-LOAD · CAT-POOR
- INTERSTATE-ERA 1950–1979
- TIMBER Wood or timber
- LONG-SPAN-RUN 4 spans
- SUB-LED Substructure-led
- LOCAL-ADT Local ADT
- LIGHT-LOAD Light 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: IRR BIA RTE 13
The IRR BIA RTE 13 bridge in Glacier, Montana carries IRR BIA RTE 13 over SOUTH FORK MILK RIVER. It was built in 1979, making it 47 years old today. The structure is built primarily of wood or timber and spans 4 sections, stretching 31.1 meters (102 feet) end to end. Daily traffic averages 60 vehicles, placing it in the lower-traffic tier of Montana bridges. It is owned and maintained by Bureau of Indian Affairs.
The latest FHWA inspection records show a deck rating of 5/9, superstructure at 5/9, 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 IRR BIA RTE 13 compares
Age against the county: built in 1979, earlier than 31 of Glacier's 71 bridges with a recorded construction year (44%), against a county median build year of 1973. This is one of the newer structures in its county.
Live comparison across Montana bridges with a recorded inventory load rating (5,144 of 5,224 rated).
IRR BIA RTE 13 vs every rated Montana bridge
Inventory load rating (metric tons), FHWA NBI, this state
7 Top 98% higher than 2% 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.
Glacier inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 71 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
- 1979
- Material
- Wood or Timber
- Number of Spans
- 4
- Structure Length
- 31.1 m (102 ft)
- Deck Width
- 7.8 m (26 ft)
- Owner
- Bureau of Indian Affairs
- Avg Daily Traffic
- 60 vehicles/day
- Structure Number
- 00000000000C130
Condition Analysis
- • The deck (driving surface) rates fair at 5/9, minor deterioration that routine maintenance should address.
- • At 5/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
- • 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
IRR BIA RTE 13 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 IRR BIA RTE 13 against other structures in Glacier 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 IRR BIA RTE 13?
IRR BIA RTE 13 in Glacier, Montana has a deck rating of 5/9, superstructure rating of 5/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.
How often is IRR BIA RTE 13 inspected?
IRR BIA RTE 13'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 60 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. IRR BIA RTE 13 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 IRR BIA RTE 13?
IRR BIA RTE 13 has an NBI inventory load rating of 6.5 metric tons.
Who is responsible for maintaining IRR BIA RTE 13?
IRR BIA RTE 13 is owned and maintained by Bureau of Indian Affairs.
How old is IRR BIA RTE 13 and does age affect safety?
IRR BIA RTE 13 was built in 1979, making it 47 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.