# Relationship history for MSHA mine 3901363

Current hierarchy: **Lac Minerals Ltd → Lac Minerals (Usa) Inc → RICHMOND HILL MINE**

- 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:** Lac Minerals (Usa) Inc → RICHMOND HILL MINE; 1988-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lac Minerals Ltd → RICHMOND HILL MINE; 1988-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lac Minerals Ltd → Lac Minerals (Usa) Inc; 1988-05-01 to current/open; source msha-controller-operator-history