# Relationship history for MSHA mine 1800373

Current hierarchy: **Ross Stuart R → Eastern Mining Systems Inc → No 1**

- 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:** Bessemer Iron & Coal Company → No 1; 1950-01-01 to 1977-08-28; source msha-controller-operator-history
- **controller_controls_mine:** James  Clark → No 1; 1950-01-01 to 1977-08-28; source msha-controller-operator-history
- **controller_controls_operator:** James  Clark → Bessemer Iron & Coal Company; 1950-01-01 to 1977-08-28; source msha-controller-operator-history
- **operator_operates_mine:** Savage Mining Company → No 1; 1977-08-29 to 1979-07-05; source msha-controller-operator-history
- **controller_controls_mine:** Bessemer Iron & Coal Company → No 1; 1977-08-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bessemer Iron & Coal Company → Savage Mining Company; 1977-08-29 to 1979-07-05; source msha-controller-operator-history
- **operator_operates_mine:** Eastern Mining Systems Inc → No 1; 1979-07-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ross Stuart R → No 1; 1979-07-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ross Stuart R → Eastern Mining Systems Inc; 1979-07-06 to current/open; source msha-controller-operator-history