# Relationship history for MSHA mine 1502552

Current hierarchy: **Gray Ancil → Solid Coal Company → No 1 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Solid Coal Company → No 1 Mine; 1950-01-01 to 1972-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Rogers James → No 1 Mine; 1950-01-01 to 1972-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Rogers James → Solid Coal Company; 1950-01-01 to 1972-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Solid Coal Company → No 1 Mine; 1972-05-01 to 1972-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Helton Joyce → No 1 Mine; 1972-05-01 to 1972-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Helton Joyce → Solid Coal Company; 1972-05-01 to 1972-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Solid Coal Company → No 1 Mine; 1972-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gray Ancil → No 1 Mine; 1972-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gray Ancil → Solid Coal Company; 1972-07-01 to current/open; source msha-controller-operator-history