# Relationship history for MSHA mine 2501330

Current hierarchy: **Zachary  Richards; Beau  Richards → Richards Gravel Pit, INC → Richards Gravel Pit, 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

- **controller_controls_mine:** Derek  Richards et al → Richards Gravel Pit, INC; 2012-08-13 to 2024-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Beau  Richards et al → Richards Gravel Pit, INC; 2025-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Richards Gravel Pit, INC → Richards Gravel Pit, INC; 2025-03-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Derek  Richards et al → Richards Gravel Pit, INC; 2025-03-24 to 2024-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Alicia  Richards et al → Richards Gravel Pit, INC; 2025-03-24 to 2024-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Beau  Richards et al → Richards Gravel Pit, INC; 2025-03-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Zachary  Richards et al → Richards Gravel Pit, INC; 2025-03-24 to current/open; source msha-controller-operator-history