# Relationship history for MSHA mine 4103468

Current hierarchy: **Mc Cormick Charles W → Mc Cormick Sand Company → Mc Cormick Sand 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:** Mansfield Sand Company → Mc Cormick Sand Pit; 1987-05-01 to 1988-07-20; source msha-controller-operator-history
- **controller_controls_mine:** Mansfield A B → Mc Cormick Sand Pit; 1987-05-01 to 1988-07-20; source msha-controller-operator-history
- **controller_controls_operator:** Mansfield A B → Mansfield Sand Company; 1987-05-01 to 1988-07-20; source msha-controller-operator-history
- **operator_operates_mine:** Mc Cormick Sand Company → Mc Cormick Sand Pit; 1988-07-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mc Cormick Charles W → Mc Cormick Sand Pit; 1988-07-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Cormick Charles W → Mc Cormick Sand Company; 1988-07-21 to current/open; source msha-controller-operator-history