# Relationship history for MSHA mine 1510650

Current hierarchy: **Geary Donald C → Geary Brothers Coal Company → Pleasant Rock Mine**

- 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:** Aberdeen Coal Company → Pleasant Rock Mine; 1977-06-01 to 1977-09-05; source msha-controller-operator-history
- **controller_controls_mine:** Crick Linvel J & Jerry L → Pleasant Rock Mine; 1977-06-01 to 1977-09-05; source msha-controller-operator-history
- **controller_controls_operator:** Crick Linvel J & Jerry L → Aberdeen Coal Company; 1977-06-01 to 1977-09-05; source msha-controller-operator-history
- **operator_operates_mine:** Geary Brothers Coal Company → Pleasant Rock Mine; 1977-09-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Geary Donald C → Pleasant Rock Mine; 1977-09-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Geary Donald C → Geary Brothers Coal Company; 1977-09-06 to current/open; source msha-controller-operator-history