# Relationship history for MSHA mine 4406218

Current hierarchy: **Williams Corp Of Virginia → Williams Corp Of Virginia → Munden Pit**

- 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:** Virginia Beach Sand Company → Munden Pit; 1985-05-01 to 1989-12-04; source msha-controller-operator-history
- **controller_controls_mine:** Munden Cameron → Munden Pit; 1985-05-01 to 1989-12-04; source msha-controller-operator-history
- **controller_controls_operator:** Munden Cameron → Virginia Beach Sand Company; 1985-05-01 to 1989-12-04; source msha-controller-operator-history
- **operator_operates_mine:** Williams Corp Of Virginia → Munden Pit; 1989-12-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Williams Corp Of Virginia → Munden Pit; 1989-12-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Williams Corp Of Virginia → Williams Corp Of Virginia; 1989-12-05 to current/open; source msha-controller-operator-history