# Relationship history for MSHA mine 3303771

Current hierarchy: **Potter Robert E → Eastern Fuel Services Inc → Prior**

- 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:** Omega Coal Corp → Prior; 1979-09-01 to 1980-09-25; source msha-controller-operator-history
- **controller_controls_mine:** Ginsburg Alan → Prior; 1979-09-01 to 1981-10-25; source msha-controller-operator-history
- **controller_controls_operator:** Ginsburg Alan → Omega Coal Corp; 1979-09-01 to 1980-09-25; source msha-controller-operator-history
- **operator_operates_mine:** Invesco Of Ohio Inc → Prior; 1980-09-26 to 1981-11-18; source msha-controller-operator-history
- **controller_controls_mine:** Invesco International Corp → Prior; 1980-09-26 to 1981-11-18; source msha-controller-operator-history
- **controller_controls_operator:** Invesco International Corp → Invesco Of Ohio Inc; 1980-09-26 to 1981-11-18; source msha-controller-operator-history
- **operator_operates_mine:** Charles Roberts Excavating → Prior; 1981-11-19 to 1982-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Roberts Charles → Prior; 1981-11-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roberts Charles → Charles Roberts Excavating; 1981-11-19 to 1982-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Potter Robert E → Prior; 1982-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Eastern Fuel Services Inc → Prior; 1982-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Potter Robert E → Eastern Fuel Services Inc; 1982-08-23 to current/open; source msha-controller-operator-history