# Relationship history for MSHA mine 3602578

Current hierarchy: **Gill Donald → Alpha Environmental Mining Corp → East Brady Strip**

- 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:** Edwin W Toy Coal Company → East Brady Strip; 1950-01-01 to 1975-04-21; source msha-controller-operator-history
- **controller_controls_mine:** Toy Edwin W Coal Company → East Brady Strip; 1950-01-01 to 1975-04-21; source msha-controller-operator-history
- **controller_controls_operator:** Toy Edwin W Coal Company → Edwin W Toy Coal Company; 1950-01-01 to 1975-04-21; source msha-controller-operator-history
- **operator_operates_mine:** Alpha Environmental Mining Corp → East Brady Strip; 1975-04-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gill Donald → East Brady Strip; 1975-04-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gill Donald → Alpha Environmental Mining Corp; 1975-04-22 to current/open; source msha-controller-operator-history