# Relationship history for MSHA mine 1700464

Current hierarchy: **Chadbourne P H → P H Chadbourne & Company → Mexico Pit**

- 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:** Chadbourne P H → Mexico Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** P H Chadbourne & Company → Mexico Pit; 1978-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chadbourne P H → P H Chadbourne & Company; 1978-03-09 to current/open; source msha-controller-operator-history