# Relationship history for MSHA mine 1511779

Current hierarchy: **Cope Darrell W → Cope Mining Company → Cope Mining Company 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Cope Mining Company → Cope Mining Company Strip; 1979-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cope Darrell W → Cope Mining Company Strip; 1979-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cope Darrell W → Cope Mining Company; 1979-03-01 to current/open; source msha-controller-operator-history