# Relationship history for MSHA mine 4604528

Current hierarchy: **Pittston Company → Excel Development Inc → #2 Surface**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Groves S J & Sons Company → #2 Surface; 1974-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Gopher Mining Company → #2 Surface; 1975-02-17 to 1977-04-12; source msha-controller-operator-history
- **controller_controls_operator:** Groves S J & Sons Company → Gopher Mining Company; 1975-02-17 to 1977-04-12; source msha-controller-operator-history
- **operator_operates_mine:** Eagle Mining Industries Inc → #2 Surface; 1977-04-13 to 1977-08-17; source msha-controller-operator-history
- **controller_controls_mine:** Eagle Coal & Dock Company Inc → #2 Surface; 1977-04-13 to 1980-01-09; source msha-controller-operator-history
- **controller_controls_operator:** Eagle Coal & Dock Company Inc → Eagle Mining Industries Inc; 1977-04-13 to 1977-08-17; source msha-controller-operator-history
- **operator_operates_mine:** Excel Development Inc → #2 Surface; 1977-08-18 to 1979-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Evergreen Industries Inc → #2 Surface; 1977-08-18 to 1979-10-31; source msha-controller-operator-history
- **controller_controls_operator:** Evergreen Industries Inc → Excel Development Inc; 1977-08-18 to 1979-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Pittston Company → #2 Surface; 1979-06-16 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Excel Development Inc → #2 Surface; 1979-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pittston Company → Excel Development Inc; 1979-07-01 to current/open; source msha-controller-operator-history