# Relationship history for MSHA mine 3605031

Current hierarchy: **Pennsylvania Power & Light Company → Greenwich Collieries-Div/Pa Mines Corp → Main Complex**

- 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:** Pennsylvania Power & Light Company → Main Complex; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Rochester & Pittsburgh Coal Company → Main Complex; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Greenwich Collieries-Div/Pa Mines Corp → Main Complex; 1974-03-26 to 1985-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Pennsylvania Power & Light Company → Greenwich Collieries-Div/Pa Mines Corp; 1974-03-26 to 1985-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Rochester & Pittsburgh Coal Company → Main Complex; 1986-01-01 to 1992-03-27; source msha-controller-operator-history
- **controller_controls_operator:** Rochester & Pittsburgh Coal Company → Rochester & Pittsburgh Coal Company; 1986-01-01 to 1992-03-27; source msha-controller-operator-history
- **operator_operates_mine:** Greenwich Collieries-Div/Pa Mines Corp → Main Complex; 1992-03-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pennsylvania Power & Light Company → Greenwich Collieries-Div/Pa Mines Corp; 1992-03-28 to current/open; source msha-controller-operator-history