# Relationship history for MSHA mine 1502800

Current hierarchy: **Thacker Glen → Thacker 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Mitchell Coal Company Inc → No 1 Mine; 1950-01-01 to 1972-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Mitchell Berry → No 1 Mine; 1950-01-01 to 1972-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Mitchell Berry → Mitchell Coal Company Inc; 1950-01-01 to 1972-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Charles  Turner → No 1 Mine; 1950-01-01 to 1976-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Dry Lake Coal Company Inc → No 1 Mine; 1972-02-01 to 1973-06-18; source msha-controller-operator-history
- **controller_controls_operator:** Charles  Turner → Dry Lake Coal Company Inc; 1972-02-01 to 1973-06-18; source msha-controller-operator-history
- **operator_operates_mine:** Roark Coal Company → No 1 Mine; 1973-06-19 to 1973-10-22; source msha-controller-operator-history
- **controller_controls_mine:** Roark Coal Company → No 1 Mine; 1973-06-19 to 1973-10-22; source msha-controller-operator-history
- **controller_controls_operator:** Roark Coal Company → Roark Coal Company; 1973-06-19 to 1973-10-22; source msha-controller-operator-history
- **operator_operates_mine:** Worley Coal Company → No 1 Mine; 1973-10-23 to 1976-07-21; source msha-controller-operator-history
- **controller_controls_mine:** Worley Coal Company → No 1 Mine; 1973-10-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Worley Coal Company → Worley Coal Company; 1973-10-23 to 1976-07-21; source msha-controller-operator-history
- **controller_controls_mine:** Thacker Glen → No 1 Mine; 1976-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Thacker Coal Company → No 1 Mine; 1976-07-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thacker Glen → Thacker Coal Company; 1976-07-22 to current/open; source msha-controller-operator-history