# Relationship history for MSHA mine 3301710

Current hierarchy: **Myron  Oswalt → Young's Sand & Gravel Co → Young's Sand & Gravel 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:** Young's Sand & Gravel Company Inc → Young's Sand & Gravel Inc.; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Young Milton R & Delmar F → Young's Sand & Gravel Inc.; 1950-01-01 to 2002-08-25; source msha-controller-operator-history
- **controller_controls_operator:** Young Milton R & Delmar F → Young's Sand & Gravel Company Inc; 1950-01-01 to 2002-08-25; source msha-controller-operator-history
- **controller_controls_mine:** Myron  Oswalt → Young's Sand & Gravel Inc.; 2002-08-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Myron  Oswalt → Young's Sand & Gravel Company Inc; 2002-08-26 to current/open; source msha-controller-operator-history