# Relationship history for MSHA mine 1300623

Current hierarchy: **Heronimus David L → Heronimus Sand & Gravel Inc → Heronimus Sand & Gravel Pit**

- 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:** Kenneth W Bowers Sand Company → Heronimus Sand & Gravel Pit; 1950-01-01 to 1983-05-22; source msha-controller-operator-history
- **controller_controls_mine:** Bowers Kenneth W → Heronimus Sand & Gravel Pit; 1950-01-01 to 1983-05-22; source msha-controller-operator-history
- **controller_controls_operator:** Bowers Kenneth W → Kenneth W Bowers Sand Company; 1950-01-01 to 1983-05-22; source msha-controller-operator-history
- **operator_operates_mine:** Heronimus Sand & Gravel Inc → Heronimus Sand & Gravel Pit; 1983-05-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Heronimus David L → Heronimus Sand & Gravel Pit; 1983-05-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heronimus David L → Heronimus Sand & Gravel Inc; 1983-05-23 to current/open; source msha-controller-operator-history