# Relationship history for MSHA mine 1600973

Current hierarchy: **Margie  Ellis; Pat  Ellis → A-1 Sand & Gravel Llc → PLANT 12**

- 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-1 Sand & Gravel Llc → PLANT 12; 1980-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Pat  Ellis  et al → PLANT 12; 2000-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pat  Ellis  et al → A-1 Sand & Gravel Llc; 2000-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Margie  Ellis  et al → A-1 Sand & Gravel Llc; 2000-07-12 to current/open; source msha-controller-operator-history