# Relationship history for MSHA mine 4606377

Current hierarchy: **Sutton William J Jr → Union Grant Coal & Stone Inc → No 1**

- 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

- **operator_operates_mine:** Union Grant Coal & Stone Inc → No 1; 1981-06-01 to 1982-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Lambert Jack → No 1; 1981-06-01 to 1982-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Lambert Jack → Union Grant Coal & Stone Inc; 1981-06-01 to 1982-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Union Grant Coal & Stone Inc → No 1; 1982-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sutton William J Jr → No 1; 1982-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sutton William J Jr → Union Grant Coal & Stone Inc; 1982-10-01 to current/open; source msha-controller-operator-history