# Relationship history for MSHA mine 1507133

Current hierarchy: **Massey Energy Company → Stone Mining Company → B-2**

- 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:** Pittston Company → B-2; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Eastern Coal Corp → B-2; 1974-01-01 to 1993-02-22; source msha-controller-operator-history
- **controller_controls_operator:** Pittston Company → Eastern Coal Corp; 1974-01-01 to 1993-02-22; source msha-controller-operator-history
- **operator_operates_mine:** Stone Mining Company → B-2; 1993-02-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Massey Energy Company → B-2; 1993-02-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Stone Mining Company; 1993-02-23 to current/open; source msha-controller-operator-history