# Relationship history for MSHA mine 0300404

Current hierarchy: **Mark  Wallis → Ouachita Gravel Company Inc → Beauchamp Pit & 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:** Malvern Gravel Company → Beauchamp Pit & Plant; 1950-01-01 to 1979-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Sam R  Clark → Beauchamp Pit & Plant; 1950-01-01 to 1979-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Sam R  Clark → Malvern Gravel Company; 1950-01-01 to 1979-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Mark  Wallis → Beauchamp Pit & Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ouachita Gravel Company Inc → Beauchamp Pit & Plant; 1979-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark  Wallis → Ouachita Gravel Company Inc; 1979-06-01 to current/open; source msha-controller-operator-history