# Relationship history for MSHA mine 4604491

Current hierarchy: **Mc Kee Kenneth → J & J Coal Company Inc → No 21 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

- **controller_controls_mine:** Mc Kee Kenneth Et Al → No 21 Mine; 1974-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** J & J Coal Company Inc → No 21 Mine; 1975-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Kee Kenneth Et Al → J & J Coal Company Inc; 1975-01-01 to current/open; source msha-controller-operator-history