# Relationship history for MSHA mine 4407271

Current hierarchy: **Bryant  Byrd; Ronald L  Byrd → R L Byrd Properties LLC → Byrd Sand**

- 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:** R L Byrd Properties LLC → Byrd Sand; 2010-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ronald L  Byrd et al → Byrd Sand; 2010-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ronald L  Byrd et al → R L Byrd Properties LLC; 2010-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bryant  Byrd et al → R L Byrd Properties LLC; 2010-06-18 to current/open; source msha-controller-operator-history