# Relationship history for MSHA mine 4403170

Current hierarchy: **Polycor Inc → Polycor Virginia Inc → Alberene Soapstone Company**

- 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:** Alberene Stone Company → Alberene Soapstone Company; 1950-01-01 to 2013-10-27; source msha-controller-operator-history
- **controller_controls_mine:** Wilkins Vance Jr → Alberene Soapstone Company; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wilkins Vance Jr → Alberene Stone Company; 1950-01-01 to 2013-10-27; source msha-controller-operator-history
- **operator_operates_mine:** Virginia Soapstone Ventures → Alberene Soapstone Company; 2013-10-28 to 2014-01-22; source msha-controller-operator-history
- **controller_controls_mine:** William C  Crane et al → Alberene Soapstone Company; 2013-10-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William C  Crane et al → Virginia Soapstone Ventures; 2013-10-28 to 2014-01-22; source msha-controller-operator-history
- **controller_controls_operator:** National Stone LLC et al → Virginia Soapstone Ventures; 2013-10-28 to 2014-01-22; source msha-controller-operator-history
- **operator_operates_mine:** Polycor Virginia Inc → Alberene Soapstone Company; 2014-01-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Polycor Inc → Alberene Soapstone Company; 2014-01-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Polycor Inc → Polycor Virginia Inc; 2014-01-23 to current/open; source msha-controller-operator-history