# Relationship history for MSHA mine 1515181

Current hierarchy: **Watts Marvin → Southern Hills Mining Company Inc → #1 Deep Mine Southern Hills Mining**

- 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:** Johnson Ralph → #1 Deep Mine Southern Hills Mining; 1984-10-24 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Southern Hills Mining Company Inc → #1 Deep Mine Southern Hills Mining; 1985-04-01 to 1987-08-19; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Ralph → Southern Hills Mining Company Inc; 1985-04-01 to 1987-08-19; source msha-controller-operator-history
- **operator_operates_mine:** Southern Hills Mining Company Inc → #1 Deep Mine Southern Hills Mining; 1987-08-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Watts Marvin → #1 Deep Mine Southern Hills Mining; 1987-08-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Watts Marvin → Southern Hills Mining Company Inc; 1987-08-20 to current/open; source msha-controller-operator-history