# Relationship history for MSHA mine 5001555

Current hierarchy: **Diane J  Ebenal → Ace II General Contractors → Ace 2 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:** A C E General Contractors Inc → Ace 2 Pit; 1988-06-01 to 2022-04-24; source msha-controller-operator-history
- **controller_controls_mine:** Alice C  Ellingson → Ace 2 Pit; 1988-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alice C  Ellingson → A C E General Contractors Inc; 1988-06-01 to 2022-04-24; source msha-controller-operator-history
- **controller_controls_mine:** Diane J  Ebenal → Ace 2 Pit; 2022-04-24 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ace II General Contractors → Ace 2 Pit; 2022-04-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Diane J  Ebenal → Ace II General Contractors; 2022-04-25 to current/open; source msha-controller-operator-history