# Relationship history for MSHA mine 1201890

Current hierarchy: **Coleman Denzil & Mack Gabbard → Earth Coal Company Inc → Lengacher Mine No 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Coleman Denzil & Mack Gabbard → Lengacher Mine No 1; 1980-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Earth Coal Company Inc → Lengacher Mine No 1; 1982-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Coleman Denzil & Mack Gabbard → Earth Coal Company Inc; 1982-06-01 to current/open; source msha-controller-operator-history