# Relationship history for MSHA mine 4603248

Current hierarchy: **American-Hawaiian Steamship Company → Royal Coal Company → No 7 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:** Royal Coal Company → No 7 Mine; 1950-01-01 to 1982-12-16; source msha-controller-operator-history
- **controller_controls_mine:** National Bulk Carriers → No 7 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** National Bulk Carriers → Royal Coal Company; 1950-01-01 to 1982-12-16; source msha-controller-operator-history
- **operator_operates_mine:** Emmanuel Mining Inc → No 7 Mine; 1982-12-17 to 1983-05-23; source msha-controller-operator-history
- **controller_controls_mine:** Robert R  Bowling → No 7 Mine; 1982-12-17 to 1983-05-23; source msha-controller-operator-history
- **controller_controls_operator:** Robert R  Bowling → Emmanuel Mining Inc; 1982-12-17 to 1983-05-23; source msha-controller-operator-history
- **operator_operates_mine:** Royal Coal Company → No 7 Mine; 1983-05-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** American-Hawaiian Steamship Company → No 7 Mine; 1983-05-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** American-Hawaiian Steamship Company → Royal Coal Company; 1983-05-24 to current/open; source msha-controller-operator-history