# Relationship history for MSHA mine 1000042

Current hierarchy: **Poe Don M → Poe Asphalt Paving Inc → Portable Crushing Unit**

- 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:** Brown John F & Donald M Poe → Portable Crushing Unit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cay'S Rock Crushing Inc → Portable Crushing Unit; 1950-01-01 to 1981-04-05; source msha-controller-operator-history
- **controller_controls_mine:** Tenwick Cay A → Portable Crushing Unit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tenwick Cay A → Cay'S Rock Crushing Inc; 1950-01-01 to 1981-04-05; source msha-controller-operator-history
- **controller_controls_mine:** Poe Don M → Portable Crushing Unit; 1980-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Western Crushing Company → Portable Crushing Unit; 1981-04-06 to 1983-04-28; source msha-controller-operator-history
- **controller_controls_operator:** Brown John F & Donald M Poe → Western Crushing Company; 1981-04-06 to 1983-04-28; source msha-controller-operator-history
- **operator_operates_mine:** Poe Asphalt Paving Inc → Portable Crushing Unit; 1983-04-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Poe Don M → Poe Asphalt Paving Inc; 1983-04-29 to current/open; source msha-controller-operator-history