# Relationship history for MSHA mine 1502471

Current hierarchy: **Johnson Ersel → Sher-Mel Coal Company Inc → No1-A**

- 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:** United  Company → No1-A; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Southern Mining Company Inc → No1-A; 1950-01-01 to 1977-07-10; source msha-controller-operator-history
- **controller_controls_mine:** Johnson Donald T → No1-A; 1950-01-01 to 1977-07-10; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Donald T → Southern Mining Company Inc; 1950-01-01 to 1977-07-10; source msha-controller-operator-history
- **controller_controls_mine:** Jessie  Meadows → No1-A; 1975-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Southern Elkhorn Coal Corp → No1-A; 1977-07-11 to 1981-11-24; source msha-controller-operator-history
- **controller_controls_mine:** International Minerals & Chemical Corp → No1-A; 1977-07-11 to 1983-04-02; source msha-controller-operator-history
- **controller_controls_operator:** International Minerals & Chemical Corp → Southern Elkhorn Coal Corp; 1977-07-11 to 1981-11-24; source msha-controller-operator-history
- **operator_operates_mine:** Coal Valley Mining Inc → No1-A; 1981-11-25 to 1984-08-21; source msha-controller-operator-history
- **controller_controls_operator:** Jessie  Meadows → Coal Valley Mining Inc; 1981-11-25 to 1984-08-21; source msha-controller-operator-history
- **controller_controls_mine:** Johnson Ersel → No1-A; 1982-04-06 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Wellmore Coal Corp → No1-A; 1984-08-22 to 1987-07-22; source msha-controller-operator-history
- **controller_controls_operator:** United  Company → Wellmore Coal Corp; 1984-08-22 to 1987-07-22; source msha-controller-operator-history
- **operator_operates_mine:** Sher-Mel Coal Company Inc → No1-A; 1987-07-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Ersel → Sher-Mel Coal Company Inc; 1987-07-23 to current/open; source msha-controller-operator-history