# Relationship history for MSHA mine 0500345

Current hierarchy: **Holcim Ltd → Holcim (US), Inc → SLAB CANYON QUARRY**

- 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

- **controller_controls_mine:** Ideal Basic Industries Inc → SLAB CANYON QUARRY; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → SLAB CANYON QUARRY; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ernest W Munroe Contractor → SLAB CANYON QUARRY; 1978-03-09 to 1983-04-12; source msha-controller-operator-history
- **controller_controls_mine:** Ernest W Munroe → SLAB CANYON QUARRY; 1978-03-09 to 1983-04-12; source msha-controller-operator-history
- **controller_controls_operator:** Ernest W Munroe → Ernest W Munroe Contractor; 1978-03-09 to 1983-04-12; source msha-controller-operator-history
- **operator_operates_mine:** Ideal Basic Industries-Cement Division → SLAB CANYON QUARRY; 1983-04-13 to 1989-06-26; source msha-controller-operator-history
- **controller_controls_operator:** Ideal Basic Industries Inc → Ideal Basic Industries-Cement Division; 1983-04-13 to 1989-06-26; source msha-controller-operator-history
- **operator_operates_mine:** Holnam Inc → SLAB CANYON QUARRY; 1989-06-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Holnam Inc; 1989-06-27 to current/open; source msha-controller-operator-history