# Relationship history for MSHA mine 4104287

Current hierarchy: **Howell Billy → Billy Howell Inc → BILLY HOWELL INC**

- 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:** Billy Howell Inc → BILLY HOWELL INC; 2001-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Howell Billy → BILLY HOWELL INC; 2001-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Howell Billy → Billy Howell Inc; 2001-06-01 to current/open; source msha-controller-operator-history