# Relationship history for MSHA mine 1503772

Current hierarchy: **Thomas  Parsons → Parsons Coal Co → No 2-A 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:** Ram Coal Company → No 2-A Mine; 1950-01-01 to 1974-11-01; source msha-controller-operator-history
- **controller_controls_mine:** Hall J B → No 2-A Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hall J B → Ram Coal Company; 1950-01-01 to 1974-11-01; source msha-controller-operator-history
- **operator_operates_mine:** Parsons Coal Co → No 2-A Mine; 1974-11-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thomas  Parsons → No 2-A Mine; 1974-11-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas  Parsons → Parsons Coal Co; 1974-11-02 to current/open; source msha-controller-operator-history