# Relationship history for MSHA mine 4104974

Current hierarchy: **Robert  Herrin; Don  Edwards → Big Bend Minerals L. L. C. → Casa Piedra Mine**

- 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:** Big Bend Minerals L. L. C. → Casa Piedra Mine; 2012-11-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert  Herrin et al → Casa Piedra Mine; 2012-11-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Herrin et al → Big Bend Minerals L. L. C.; 2012-11-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Don  Edwards et al → Big Bend Minerals L. L. C.; 2012-11-27 to current/open; source msha-controller-operator-history