# Relationship history for MSHA mine 2301571

Current hierarchy: **Schmidt Byron → Byron Schmidt Inc → Waynesville 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

- **operator_operates_mine:** Roubidoux Sand & Gravel Inc → Waynesville Plant; 1950-01-01 to 1978-07-25; source msha-controller-operator-history
- **controller_controls_mine:** Brice Earl R → Waynesville Plant; 1950-01-01 to 1978-07-25; source msha-controller-operator-history
- **controller_controls_operator:** Brice Earl R → Roubidoux Sand & Gravel Inc; 1950-01-01 to 1978-07-25; source msha-controller-operator-history
- **operator_operates_mine:** Byron Schmidt Inc → Waynesville Plant; 1978-07-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Schmidt Byron → Waynesville Plant; 1978-07-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Schmidt Byron → Byron Schmidt Inc; 1978-07-26 to current/open; source msha-controller-operator-history