# Relationship history for MSHA mine 2602173

Current hierarchy: **York Gregg D → C M Concepts Of Nevada Inc → Cmc Of Nevada Incorporated**

- 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

- **operator_operates_mine:** C M Concepts Of Nevada Inc → Cmc Of Nevada Incorporated; 1990-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** York Gregg D → Cmc Of Nevada Incorporated; 1990-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** York Gregg D → C M Concepts Of Nevada Inc; 1990-11-01 to current/open; source msha-controller-operator-history