# Relationship history for MSHA mine 4605816

Current hierarchy: **Thecker Duncan & Lewis Ellison → Hico Mining Company → No 1 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:** Coventry Energy Corp → No 1 Mine; 1978-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ellison Coal Company Inc → No 1 Mine; 1978-10-01 to 1981-03-20; source msha-controller-operator-history
- **controller_controls_operator:** Coventry Energy Corp → Ellison Coal Company Inc; 1978-10-01 to 1981-03-20; source msha-controller-operator-history
- **operator_operates_mine:** Hico Mining Company → No 1 Mine; 1981-03-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thecker Duncan & Lewis Ellison → No 1 Mine; 1981-03-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thecker Duncan & Lewis Ellison → Hico Mining Company; 1981-03-21 to current/open; source msha-controller-operator-history