# Relationship history for MSHA mine 4102247

Current hierarchy: **Prevot A → Byrd Ranch Inc → Byrd Pit #1**

- 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:** William H Harkrider Company → Byrd Pit #1; 1950-01-01 to 1985-04-22; source msha-controller-operator-history
- **controller_controls_mine:** Harkrider William H → Byrd Pit #1; 1950-01-01 to 1985-04-22; source msha-controller-operator-history
- **controller_controls_operator:** Harkrider William H → William H Harkrider Company; 1950-01-01 to 1985-04-22; source msha-controller-operator-history
- **operator_operates_mine:** Byrd Ranch Inc → Byrd Pit #1; 1985-04-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Prevot A → Byrd Pit #1; 1985-04-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Prevot A → Byrd Ranch Inc; 1985-04-23 to current/open; source msha-controller-operator-history