# Relationship history for MSHA mine 4002640

Current hierarchy: **Chitwood Jack → T & S Products → No 1 Surface**

- 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:** Low Gap Energy Inc → No 1 Surface; 1980-09-01 to 1981-05-03; source msha-controller-operator-history
- **controller_controls_mine:** Purkey Sharon → No 1 Surface; 1980-09-01 to 1981-05-03; source msha-controller-operator-history
- **controller_controls_operator:** Purkey Sharon → Low Gap Energy Inc; 1980-09-01 to 1981-05-03; source msha-controller-operator-history
- **controller_controls_mine:** Chitwood Jack → No 1 Surface; 1980-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** T & S Products → No 1 Surface; 1981-05-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chitwood Jack → T & S Products; 1981-05-04 to current/open; source msha-controller-operator-history