# Relationship history for MSHA mine 1600964

Current hierarchy: **Johnson Max L → Johnson Boys Gravel Pit → Ellerbee Lease**

- 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

- **controller_controls_mine:** Johnson Max L → Ellerbee Lease; 1978-06-07 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Johnson Boys Gravel Pit → Ellerbee Lease; 1979-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Max L → Johnson Boys Gravel Pit; 1979-12-01 to current/open; source msha-controller-operator-history