# Relationship history for MSHA mine 4601887

Current hierarchy: **Hardesty John R Jr-Larry A Myers → Preston Energy Inc → Big Joe 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:** Y & S Coal Company Inc → Big Joe Mine; 1950-01-01 to 1974-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Y & S Coal Company Inc → Big Joe Mine; 1950-01-01 to 1974-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Y & S Coal Company Inc → Y & S Coal Company Inc; 1950-01-01 to 1974-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Hardesty John R Jr-Larry A Myers Et Al → Big Joe Mine; 1974-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Big Joe Coal Company → Big Joe Mine; 1974-06-01 to 1978-01-09; source msha-controller-operator-history
- **controller_controls_mine:** Petitte James → Big Joe Mine; 1974-06-01 to 1978-01-09; source msha-controller-operator-history
- **controller_controls_operator:** Petitte James → Big Joe Coal Company; 1974-06-01 to 1978-01-09; source msha-controller-operator-history
- **operator_operates_mine:** Preston Energy Inc → Big Joe Mine; 1978-01-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hardesty John R Jr-Larry A Myers Et Al → Preston Energy Inc; 1978-01-10 to current/open; source msha-controller-operator-history