# Relationship history for MSHA mine 3606442

Current hierarchy: **Henckel Elmer M Jr → E M Henckel Coal Company → No 2 Strip**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Henckel Elmer M Jr → No 2 Strip; 1976-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** E M Henckel Coal Company → No 2 Strip; 1977-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Henckel Elmer M Jr → E M Henckel Coal Company; 1977-06-01 to current/open; source msha-controller-operator-history