# Relationship history for MSHA mine 3607012

Current hierarchy: **Marie  Hamilton → Northern Coal & Clay Company Inc → Mull Strip**

- 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:** Francis J  Hamilton et al → Mull Strip; 1980-01-01 to 1981-10-13; source msha-controller-operator-history
- **operator_operates_mine:** Northern Coal & Clay Company Inc → Mull Strip; 1980-08-01 to 1981-10-13; source msha-controller-operator-history
- **controller_controls_operator:** Francis J  Hamilton et al → Northern Coal & Clay Company Inc; 1980-08-01 to 1981-10-13; source msha-controller-operator-history
- **operator_operates_mine:** Northern Coal & Clay Company Inc → Mull Strip; 1981-10-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Marie  Hamilton → Mull Strip; 1981-10-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Marie  Hamilton → Northern Coal & Clay Company Inc; 1981-10-14 to current/open; source msha-controller-operator-history