# Relationship history for MSHA mine 4102647

Current hierarchy: **Windham Morris B → Big Sandy Sand Pit → Big Sandy Sand Pit**

- 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:** Big Sandy Sand Pit → Big Sandy Sand Pit; 1950-01-01 to 1984-02-01; source msha-controller-operator-history
- **controller_controls_mine:** Bryson Robert H → Big Sandy Sand Pit; 1950-01-01 to 1988-07-13; source msha-controller-operator-history
- **controller_controls_operator:** Bryson Robert H → Big Sandy Sand Pit; 1950-01-01 to 1984-02-01; source msha-controller-operator-history
- **operator_operates_mine:** Little Sandy Sand Pit → Big Sandy Sand Pit; 1984-02-02 to 1985-01-29; source msha-controller-operator-history
- **controller_controls_mine:** Anderson Hill → Big Sandy Sand Pit; 1984-02-02 to 1985-12-09; source msha-controller-operator-history
- **controller_controls_operator:** Anderson Hill → Little Sandy Sand Pit; 1984-02-02 to 1985-01-29; source msha-controller-operator-history
- **operator_operates_mine:** Big Sandy Sand Pit → Big Sandy Sand Pit; 1985-01-30 to 1988-07-13; source msha-controller-operator-history
- **controller_controls_operator:** Bryson Robert H → Big Sandy Sand Pit; 1985-01-30 to 1988-07-13; source msha-controller-operator-history
- **operator_operates_mine:** Big Sandy Sand Pit → Big Sandy Sand Pit; 1988-07-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Windham Morris B → Big Sandy Sand Pit; 1988-07-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Windham Morris B → Big Sandy Sand Pit; 1988-07-14 to current/open; source msha-controller-operator-history