# Relationship history for MSHA mine 0301954

Current hierarchy: **Eric A  Byrd → Byrd's Heritage Stone → Byrd's Heritage Stone**

- 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:** Byrd Stone Company → Byrd's Heritage Stone; 2007-08-01 to 2016-06-28; source msha-controller-operator-history
- **controller_controls_mine:** Bobby A  Byrd → Byrd's Heritage Stone; 2007-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bobby A  Byrd → Byrd Stone Company; 2007-08-01 to 2016-06-28; source msha-controller-operator-history
- **operator_operates_mine:** Byrd's Heritage Stone → Byrd's Heritage Stone; 2016-06-29 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Eric A  Byrd → Byrd's Heritage Stone; 2016-06-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eric A  Byrd → Byrd's Heritage Stone; 2016-06-29 to current/open; source msha-controller-operator-history