# Relationship history for MSHA mine 1800627

Current hierarchy: **Alexander Dave → Primrose Coal Inc → Vansickle Job 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

- **controller_controls_mine:** Alexander Camille Jr → Vansickle Job Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Alexander Coal Company → Vansickle Job Mine; 1976-10-18 to 1979-01-18; source msha-controller-operator-history
- **controller_controls_operator:** Alexander Camille Jr → Alexander Coal Company; 1976-10-18 to 1979-01-18; source msha-controller-operator-history
- **controller_controls_mine:** Alexander Dave Et Al → Vansickle Job Mine; 1978-06-23 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Primrose Coal Inc → Vansickle Job Mine; 1979-01-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alexander Dave Et Al → Primrose Coal Inc; 1979-01-19 to current/open; source msha-controller-operator-history