# Relationship history for MSHA mine 1509777

Current hierarchy: **Driskill Jerry T Sr → Crown Energy Inc → Crown Energy Prep Plant**

- 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:** Crown Energy Inc → Crown Energy Prep Plant; 1976-06-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Driskill Jerry T Sr → Crown Energy Prep Plant; 1976-06-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Driskill Jerry T Sr → Crown Energy Inc; 1976-06-15 to current/open; source msha-controller-operator-history