# Relationship history for MSHA mine 1517207

Current hierarchy: **Diane  Blankenship → Crystal Colleries Inc → 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Little Pearl Coal Company Inc → No 1; 1992-03-01 to 1994-10-03; source msha-controller-operator-history
- **controller_controls_mine:** Bowman Warren → No 1; 1992-03-01 to 1994-10-03; source msha-controller-operator-history
- **controller_controls_operator:** Bowman Warren → Little Pearl Coal Company Inc; 1992-03-01 to 1994-10-03; source msha-controller-operator-history
- **operator_operates_mine:** Elizabeth Coal Inc → No 1; 1994-10-04 to 1995-08-16; source msha-controller-operator-history
- **controller_controls_mine:** Bowman Danny → No 1; 1994-10-04 to 1995-08-16; source msha-controller-operator-history
- **controller_controls_operator:** Bowman Danny → Elizabeth Coal Inc; 1994-10-04 to 1995-08-16; source msha-controller-operator-history
- **operator_operates_mine:** Sweet Ruby Mining Inc → No 1; 1995-08-17 to 1996-03-04; source msha-controller-operator-history
- **controller_controls_mine:** Lester Thomas → No 1; 1995-08-17 to 1996-03-04; source msha-controller-operator-history
- **controller_controls_operator:** Lester Thomas → Sweet Ruby Mining Inc; 1995-08-17 to 1996-03-04; source msha-controller-operator-history
- **operator_operates_mine:** Crystal Colleries Inc → No 1; 1996-03-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Diane  Blankenship → No 1; 1996-03-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Diane  Blankenship → Crystal Colleries Inc; 1996-03-05 to current/open; source msha-controller-operator-history