# Relationship history for MSHA mine 4606979

Current hierarchy: **Volk Joseph A & James W Stone → Volkstone Company → Volkstone Mine #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:** Volkstone Company → Volkstone Mine #1; 1985-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Volk Joseph A & James W Stone → Volkstone Mine #1; 1985-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Volk Joseph A & James W Stone → Volkstone Company; 1985-08-01 to current/open; source msha-controller-operator-history