# Relationship history for MSHA mine 1509756

Current hierarchy: **Barnwell Darrell G → Burnside Excavating Company Inc → Poplar Lick 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:** Burnside Excavating Company Inc → Poplar Lick Strip; 1976-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Barnwell Darrell G → Poplar Lick Strip; 1976-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Barnwell Darrell G → Burnside Excavating Company Inc; 1976-06-01 to current/open; source msha-controller-operator-history