# Relationship history for MSHA mine 1516910

Current hierarchy: **James A  Hubbard → Hasco Inc → Sterling 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:** Sturgill Leslie → Sterling Mine; 1981-04-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ball Ralph → Sterling Mine; 1981-06-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John H  Parton → Sterling Mine; 1990-02-01 to 1997-01-01; source msha-controller-operator-history
- **operator_operates_mine:** Switch Energy Corp → Sterling Mine; 1990-07-01 to 1994-11-27; source msha-controller-operator-history
- **controller_controls_operator:** Sturgill Leslie → Switch Energy Corp; 1990-07-01 to 1994-11-27; source msha-controller-operator-history
- **operator_operates_mine:** T J Mining Inc → Sterling Mine; 1994-11-28 to 1997-01-01; source msha-controller-operator-history
- **controller_controls_operator:** John H  Parton → T J Mining Inc; 1994-11-28 to 1997-01-01; source msha-controller-operator-history
- **operator_operates_mine:** Sterling Energy Inc → Sterling Mine; 1997-01-02 to 1997-11-02; source msha-controller-operator-history
- **controller_controls_operator:** Ball Ralph → Sterling Energy Inc; 1997-01-02 to 1997-11-02; source msha-controller-operator-history
- **operator_operates_mine:** Hasco Inc → Sterling Mine; 1997-11-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James A  Hubbard → Sterling Mine; 1997-11-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James A  Hubbard → Hasco Inc; 1997-11-03 to current/open; source msha-controller-operator-history