# Relationship history for MSHA mine 1516766

Current hierarchy: **Dennis  Ratliff; Timmy  Ratliff → Black Hawk Coal Corp → 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

- **controller_controls_mine:** Blankenship Virgus → No 1; 1977-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tri-Star Mining Company Inc → No 1; 1989-11-01 to 1993-07-05; source msha-controller-operator-history
- **controller_controls_operator:** Blankenship Virgus → Tri-Star Mining Company Inc; 1989-11-01 to 1993-07-05; source msha-controller-operator-history
- **operator_operates_mine:** Black Hawk Coal Corp → No 1; 1993-07-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dennis  Ratliff et al → No 1; 1993-07-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dennis  Ratliff et al → Black Hawk Coal Corp; 1993-07-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Timmy  Ratliff et al → Black Hawk Coal Corp; 1993-07-06 to current/open; source msha-controller-operator-history