# Relationship history for MSHA mine 1400543

Current hierarchy: **Summit Materials LLC → Cornejo & Sons LLC → Wichita Sand and Gravel**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Ritchie Sand Inc → Wichita Sand and Gravel; 1950-01-01 to 2005-11-30; source msha-controller-operator-history
- **controller_controls_mine:** H T  Ritchie → Wichita Sand and Gravel; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** H T  Ritchie → Ritchie Sand Inc; 1950-01-01 to 2005-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Wichita Sand and Gravel; 2001-07-12 to 2015-07-09; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge North America Inc → Wichita Sand and Gravel; 2005-12-01 to 2013-04-01; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge North America Inc; 2005-12-01 to 2013-04-01; source msha-controller-operator-history
- **controller_controls_mine:** Summit Materials LLC → Wichita Sand and Gravel; 2011-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cornejo & Sons LLC → Wichita Sand and Gravel; 2013-04-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Summit Materials LLC → Cornejo & Sons LLC; 2013-04-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → Wichita Sand and Gravel; 2015-07-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Lafarge North America Inc; 2015-07-10 to 2013-04-01; source msha-controller-operator-history