# Relationship history for MSHA mine 2902289

Current hierarchy: **Charlene G  Alcon → Alcon Sand & Gravel → Alcon Sand & 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Alcon Sand & Gravel → Alcon Sand & Gravel; 2005-08-10 to 2025-04-10; source msha-controller-operator-history
- **controller_controls_mine:** Clyde  Alcon → Alcon Sand & Gravel; 2005-08-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Clyde  Alcon → Alcon Sand & Gravel; 2005-08-10 to 2025-04-10; source msha-controller-operator-history
- **operator_operates_mine:** Alcon Sand & Gravel → Alcon Sand & Gravel; 2025-04-11 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Charlene G  Alcon → Alcon Sand & Gravel; 2025-04-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Charlene G  Alcon → Alcon Sand & Gravel; 2025-04-11 to current/open; source msha-controller-operator-history