# Relationship history for MSHA mine 2601495

Current hierarchy: **Johnston Thomas C → Merodach Consulting → Johnston 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

- **controller_controls_mine:** David L  Pruett → Johnston Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Mineop Corp → Johnston Mine; 1978-03-09 to 1979-10-16; source msha-controller-operator-history
- **controller_controls_operator:** David L  Pruett → Mineop Corp; 1978-03-09 to 1979-10-16; source msha-controller-operator-history
- **operator_operates_mine:** Dalex International → Johnston Mine; 1979-10-17 to 1986-04-13; source msha-controller-operator-history
- **controller_controls_mine:** Viverant Robert → Johnston Mine; 1979-10-17 to 1986-04-13; source msha-controller-operator-history
- **controller_controls_operator:** Viverant Robert → Dalex International; 1979-10-17 to 1986-04-13; source msha-controller-operator-history
- **operator_operates_mine:** Fischer Watt Mining Company → Johnston Mine; 1986-04-14 to 1987-06-01; source msha-controller-operator-history
- **controller_controls_mine:** Watt Tim → Johnston Mine; 1986-04-14 to 1987-06-01; source msha-controller-operator-history
- **controller_controls_operator:** Watt Tim → Fischer Watt Mining Company; 1986-04-14 to 1987-06-01; source msha-controller-operator-history
- **operator_operates_mine:** Merodach Consulting → Johnston Mine; 1987-06-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Johnston Thomas C → Johnston Mine; 1987-06-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnston Thomas C → Merodach Consulting; 1987-06-02 to current/open; source msha-controller-operator-history