# Relationship history for MSHA mine 4605832

Current hierarchy: **Mc Kinney Elko J → Unity Mining Inc → Nancy Kay 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

- **operator_operates_mine:** Krystal Coal Company Inc → Nancy Kay Mine; 1978-07-01 to 1979-05-08; source msha-controller-operator-history
- **controller_controls_mine:** Ramey John V → Nancy Kay Mine; 1978-07-01 to 1979-05-08; source msha-controller-operator-history
- **controller_controls_operator:** Ramey John V → Krystal Coal Company Inc; 1978-07-01 to 1979-05-08; source msha-controller-operator-history
- **operator_operates_mine:** D A D Coal Company Inc → Nancy Kay Mine; 1979-05-09 to 1980-05-05; source msha-controller-operator-history
- **controller_controls_mine:** Adkins William → Nancy Kay Mine; 1979-05-09 to 1988-03-19; source msha-controller-operator-history
- **controller_controls_operator:** Adkins William → D A D Coal Company Inc; 1979-05-09 to 1980-05-05; source msha-controller-operator-history
- **operator_operates_mine:** Unity Mining Inc → Nancy Kay Mine; 1980-05-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mc Kinney Elko J → Nancy Kay Mine; 1980-05-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Kinney Elko J → Unity Mining Inc; 1980-05-06 to current/open; source msha-controller-operator-history