# Relationship history for MSHA mine 2902213

Current hierarchy: **Omar  Bazan → Del Norte Masonry Products → Berino Sand 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

- **controller_controls_mine:** Richard  Backer → Berino Sand Pit; 1950-01-01 to 2015-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Del Norte Masonry Products → Berino Sand Pit; 2001-01-01 to 2018-02-21; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Backer → Del Norte Masonry Products; 2001-01-01 to 2015-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Kay  Backer → Berino Sand Pit; 2015-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kay  Backer → Del Norte Masonry Products; 2015-06-01 to 2018-02-21; source msha-controller-operator-history
- **operator_operates_mine:** Del Norte Masonry Products → Berino Sand Pit; 2018-02-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Omar  Bazan → Berino Sand Pit; 2018-02-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Omar  Bazan → Del Norte Masonry Products; 2018-02-22 to current/open; source msha-controller-operator-history