# Relationship history for MSHA mine 4102784

Current hierarchy: **Vistra Energy → Txu Mining Company → Forest Grove 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:** Txu Mining Company → Forest Grove Strip; 1979-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** TXU → Forest Grove Strip; 2007-08-31 to 2007-09-30; source msha-controller-operator-history
- **controller_controls_operator:** TXU → Txu Mining Company; 2007-08-31 to 2007-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Energy Future Holdings Corporation → Forest Grove Strip; 2007-10-01 to 2016-10-03; source msha-controller-operator-history
- **controller_controls_operator:** Energy Future Holdings Corporation → Txu Mining Company; 2007-10-01 to 2016-10-03; source msha-controller-operator-history
- **controller_controls_mine:** Vistra Energy → Forest Grove Strip; 2016-10-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vistra Energy → Txu Mining Company; 2016-10-04 to current/open; source msha-controller-operator-history