# Relationship history for MSHA mine 2300684

Current hierarchy: **Vernon J  Bauman → Base Rock Materials Inc → Bauman 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:** Bauman Oil & Materials Inc → Bauman Sand & Gravel; 1950-01-01 to 1991-07-11; source msha-controller-operator-history
- **controller_controls_mine:** Bauman Charles L → Bauman Sand & Gravel; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bauman Charles L → Bauman Oil & Materials Inc; 1950-01-01 to 1991-07-11; source msha-controller-operator-history
- **operator_operates_mine:** Base Rock Materials Inc → Bauman Sand & Gravel; 1991-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Vernon J  Bauman → Bauman Sand & Gravel; 1991-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vernon J  Bauman → Base Rock Materials Inc; 1991-07-12 to current/open; source msha-controller-operator-history