# Relationship history for MSHA mine 4405021

Current hierarchy: **Paul R  Ison; Jessica B  Ison → Ambrose Branch Coal Company Inc → Hawthorne Dock**

- 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

- **controller_controls_mine:** Jessica B  Ison  et al → Hawthorne Dock; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ambrose Branch Coal Company Inc → Hawthorne Dock; 1978-05-01 to 2001-06-14; source msha-controller-operator-history
- **controller_controls_operator:** Jessica B  Ison  et al → Ambrose Branch Coal Company Inc; 1978-05-01 to 2001-06-14; source msha-controller-operator-history
- **controller_controls_operator:** Paul R  Ison  et al → Ambrose Branch Coal Company Inc; 1978-05-01 to 2001-06-14; source msha-controller-operator-history
- **controller_controls_mine:** Horace Garrison  Hill → Hawthorne Dock; 1995-05-16 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** D & C Mining Corp → Hawthorne Dock; 2001-06-15 to 2009-06-17; source msha-controller-operator-history
- **controller_controls_operator:** Horace Garrison  Hill → D & C Mining Corp; 2001-06-15 to 2009-06-17; source msha-controller-operator-history
- **operator_operates_mine:** Ambrose Branch Coal Company Inc → Hawthorne Dock; 2009-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Paul R  Ison  et al → Ambrose Branch Coal Company Inc; 2009-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jessica B  Ison  et al → Ambrose Branch Coal Company Inc; 2009-06-18 to current/open; source msha-controller-operator-history