# Relationship history for MSHA mine 3304399

Current hierarchy: **Johnson S E Companies Inc → Wolcottville Sand & Gravel → WOLCOTTVILLE SAND & GRAVEL PIT 1**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Johnson S E Companies Inc → WOLCOTTVILLE SAND & GRAVEL PIT 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Wolcottville Sand & Gravel → WOLCOTTVILLE SAND & GRAVEL PIT 1; 1997-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson S E Companies Inc → Wolcottville Sand & Gravel; 1997-08-01 to current/open; source msha-controller-operator-history