# Relationship history for MSHA mine 1509536

Current hierarchy: **White Ben F → New White Coal Company Inc → #1 Preparation Plant**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** New White Coal Company Inc → #1 Preparation Plant; 1976-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** White Ben F → #1 Preparation Plant; 1976-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** White Ben F → New White Coal Company Inc; 1976-03-01 to current/open; source msha-controller-operator-history