# Relationship history for MSHA mine 2002838

Current hierarchy: **Cannon Michael → Michigan Sand Company Inc → MICHIGAN SAND CO., INC.**

- 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:** Michigan Sand Company Inc → MICHIGAN SAND CO., INC.; 1989-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cannon Michael → MICHIGAN SAND CO., INC.; 1989-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cannon Michael → Michigan Sand Company Inc; 1989-11-01 to current/open; source msha-controller-operator-history