# Relationship history for MSHA mine 1507776

Current hierarchy: **Miller David H → Mark Iv Coal Inc → No 1 Surface**

- 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:** Miller David H → No 1 Surface; 1974-01-12 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Mark Iv Coal Inc → No 1 Surface; 1974-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Miller David H → Mark Iv Coal Inc; 1974-12-01 to current/open; source msha-controller-operator-history