# Relationship history for MSHA mine 4002474

Current hierarchy: **Parker Bobby G → Parker & Henderson Coal Company Inc → Parker And Henderson Coal Company Incorp**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Parker Bobby G → Parker And Henderson Coal Company Incorp; 1976-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Parker & Henderson Coal Company Inc → Parker And Henderson Coal Company Incorp; 1978-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Parker Bobby G → Parker & Henderson Coal Company Inc; 1978-11-01 to current/open; source msha-controller-operator-history