# Relationship history for MSHA mine 4201828

Current hierarchy: **CCI  (Clyde Companies Inc) → Geneva Rock Products Inc → Cove/Upper Walker 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

- **controller_controls_mine:** CCI  (Clyde Companies Inc) → Cove/Upper Walker Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Christensen Construction & Gravel Inc → Cove/Upper Walker Pit; 1983-07-01 to 2007-10-19; source msha-controller-operator-history
- **controller_controls_mine:** Dena  Christensen → Cove/Upper Walker Pit; 1983-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dena  Christensen → Christensen Construction & Gravel Inc; 1983-07-01 to 2007-10-19; source msha-controller-operator-history
- **operator_operates_mine:** Geneva Rock Products Inc → Cove/Upper Walker Pit; 2007-10-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CCI  (Clyde Companies Inc) → Geneva Rock Products Inc; 2007-10-20 to current/open; source msha-controller-operator-history