CaseTriangle1987
Yankton, SD, USA
silent isosceles triangle shaped mirage-like UFO with no lights
Report quality: Moderate51/100
This score reflects report-quality signals on file — how complete, corroborated, and precisely located the report is — not a claim about whether the sighting was a real craft.
- Duration parsed: 6s, a plausible sighting length
- Moderate witness text (63 characters)
- Location geocoded exactly
- No other reports from this city within 3 days
- When
- 1987-09-15
- Where
- Yankton, SD, USA
- Shape
- Triangle
- Duration
- 5-6 seconds
- Geo
- 42.871, -97.397 · exact
- Slug
- triangle-over-yankton-sd-1987-b51f92
In context
- Yankton, SD shows up 13 times across the archive.
- 1 reports came from South Dakota in 1987.
- In the 1980s, 12% of reports described a triangle — the all-time rate is 9%.
Report
Full narrative lands with dossier import for famous cases, or the NUFORC free-text summary above for standard reports. This shell is SSR-ready: one D1 row (including connections_json) per page.