SD ROUTE 87
Carrying SD ROUTE 87 over BEAVER CREEK
ON SD ROUTE 87, MP 41.4;, Custer, South Dakota
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: SD ROUTE 87
The SD ROUTE 87 bridge in Custer, South Dakota carries SD ROUTE 87 over BEAVER CREEK. It was built in 1929, making it 97 years old today. The structure is built primarily of concrete and spans 1 section, stretching 67.1 meters (220 feet) end to end. Daily traffic averages 326 vehicles, placing it in the lower-traffic tier of South Dakota bridges. It is owned and maintained by National Park Service.
The latest FHWA inspection records show a deck rating of 6/9, superstructure at 6/9, substructure at 6/9. The weakest component sits in fair condition. No reported major component scores in the Poor range under the current federal condition thresholds. Its NBI inventory load rating is 14.0 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How SD ROUTE 87 compares
Live comparison across South Dakota.
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 How the historical reference is calculated.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
- 1929
- Material
- Concrete
- Number of Spans
- 1
- Structure Length
- 67.1 m (220 ft)
- Deck Width
- 7.1 m (23 ft)
- Owner
- National Park Service
- Avg Daily Traffic
- 326 vehicles/day
- Structure Number
- 1560001P0000000
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗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) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
How to read this record
This page shows what the last federal inspection recorded, not whether SD ROUTE 87 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 SD ROUTE 87 against other structures in Custer and across South Dakota. South Dakota 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 SD ROUTE 87?
SD ROUTE 87 in Custer, South Dakota has a deck rating of 6/9, superstructure rating of 6/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is SD ROUTE 87 inspected?
SD ROUTE 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 326 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. SD ROUTE 87 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 SD ROUTE 87?
SD ROUTE 87 has an NBI inventory load rating of 14.0 metric tons.
Who is responsible for maintaining SD ROUTE 87?
SD ROUTE 87 is owned and maintained by National Park Service.
How old is SD ROUTE 87 and does age affect safety?
SD ROUTE 87 was built in 1929, making it 97 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.