When and where was Sylvan Lake Surface Disturbance and Sonar Search documented?

This encounter was documented on July 27, 2009 in Sylvan Lake, Minnesota, Minnesota, United States.

What sources and physical claims back the Sylvan Lake Surface Disturbance and Sonar Search record?

The ANOMALY archive indexes 0 independent source citations across 0 claims, achieving a provenance completeness score of 29%.

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ENC-902421LANDMARK CASE · HIGH CORROBORATIONDATE PRECISION: exactRECORD COMPLETENESS: 29%

Sylvan Lake Surface Disturbance and Sonar Search

Name: Sylvan Lake Surface Disturbance and Sonar Search
Start: July 27, 2009
Location: Sylvan Lake, Minnesota, United States

July 27, 2009Sylvan Lake, Minnesota, Minnesota, United States

Witness reported a linear surface disturbance, outward waves and a rotating circle in Sylvan Lake. Sheriff/fire dive teams found no crashed helicopter; side-scan sonar later returned one manufactured-looking anomaly near the marked area.

// PROVENANCE COVERAGE

29% record completeness

This measures documentation coverage, not whether the encounter or its claims are true.

0 SOURCES · 0 PRIMARY

Date documented

July 27, 2009

Location documented

Sylvan Lake, Minnesota, Minnesota, United States

Map coordinates available

No latitude/longitude is available for mapping.

Catalogue classification linked

0 family link(s), 0 case-specific component(s).

Published citation-backed claims

0 encounter-target claim(s), 0 component claim(s).

Source coverage

0 unique source edition(s); 0 marked primary for at least one claim.

Assessment has encounter-level provenance

Assessment fields exist, but no encounter-target published citation-backed claim currently supports them.

Assessment values are present without encounter-target published citation-backed claims. Treat the matrix as unprovenanced metadata until direct claims are added.

Witness totals are stored, but no encounter-level cited claim currently documents where those numbers came from.

// ASSESSMENT METADATA

Stored case-assessment fields

DIRECT PROVENANCE INCOMPLETE

Stored total witness estimate1

Stored verified-report count0

Instrumental evidence flagYES

Official investigation flagYES

These stored assessment values are shown transparently but should not be treated as source-backed facts until encounter-target claims cite their provenance.