# Relationship history for MSHA mine 4105545

Current hierarchy: **Cord  Johnson → Bighorn Sand and Gravel, LLC → Mestino**

- 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:** Bighorn Sand and Gravel, LLC → Mestino; 2021-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cord  Johnson → Mestino; 2021-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cord  Johnson → Bighorn Sand and Gravel, LLC; 2021-02-01 to current/open; source msha-controller-operator-history