# Relationship history for MSHA mine 0405681

Current hierarchy: **Chester M  Roberts → Borrego Sand & Rock Inc → Rodriguez Borrow 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Borrego Sand & Rock Inc → Rodriguez Borrow Pit; 2006-04-10 to 2007-03-12; source msha-controller-operator-history
- **controller_controls_mine:** Elizabeth  Riis → Rodriguez Borrow Pit; 2006-04-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Elizabeth  Riis → Borrego Sand & Rock Inc; 2006-04-10 to 2007-03-12; source msha-controller-operator-history
- **operator_operates_mine:** Borrego Sand & Rock Inc → Rodriguez Borrow Pit; 2007-03-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Chester M  Roberts et al → Rodriguez Borrow Pit; 2007-03-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chester M  Roberts et al → Borrego Sand & Rock Inc; 2007-03-13 to current/open; source msha-controller-operator-history