# Relationship history for MSHA mine 4407028

Current hierarchy: **Progress Energy Inc → Powell Mountain Coal Co. Inc → PMRS**

- 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:** Progress Energy Inc → PMRS; 2000-11-30 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Powell Mountain Coal Co. Inc → PMRS; 2001-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Progress Energy Inc → Powell Mountain Coal Co. Inc; 2001-05-01 to current/open; source msha-controller-operator-history