# Relationship history for MSHA mine 4104578

Current hierarchy: **Michael B  Arnold → Arnold Crushed Stone Inc → Tolar Plant**

- 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

- **controller_controls_mine:** Michael B  Arnold → Tolar Plant; 1996-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Arnold Crushed Stone Inc → Tolar Plant; 2006-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael B  Arnold → Arnold Crushed Stone Inc; 2006-02-28 to current/open; source msha-controller-operator-history