# Relationship history for MSHA mine 1401539

Current hierarchy: **Summit Materials LLC → Midwest Minerals → Grove**

- 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:** Quik Sand Inc → Grove; 1990-06-01 to 1995-01-29; source msha-controller-operator-history
- **controller_controls_mine:** George A  Pearson Jr → Grove; 1990-06-01 to 1995-01-29; source msha-controller-operator-history
- **controller_controls_operator:** George A  Pearson Jr → Quik Sand Inc; 1990-06-01 to 1995-01-29; source msha-controller-operator-history
- **operator_operates_mine:** Cornejo Materials Inc → Grove; 1995-01-30 to 2010-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Cornejo & Sons Inc → Grove; 1995-01-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cornejo & Sons Inc → Cornejo Materials Inc; 1995-01-30 to 2010-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Midwest Minerals → Grove; 2011-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Summit Materials LLC → Grove; 2011-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Summit Materials LLC → Midwest Minerals; 2011-01-01 to current/open; source msha-controller-operator-history