# Relationship history for MSHA mine 4606152

Current hierarchy: **Imperial-Pacific Investments Inc → Princess Susan Coal Company → Frozen Branch Surface**

- 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:** Central Penn Industries Inc → Frozen Branch Surface; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Princess Susan Coal Company → Frozen Branch Surface; 1980-05-01 to 1983-11-22; source msha-controller-operator-history
- **controller_controls_operator:** Central Penn Industries Inc → Princess Susan Coal Company; 1980-05-01 to 1983-11-22; source msha-controller-operator-history
- **operator_operates_mine:** Princess Susan Coal Company → Frozen Branch Surface; 1983-11-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Imperial-Pacific Investments Inc → Frozen Branch Surface; 1983-11-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Imperial-Pacific Investments Inc → Princess Susan Coal Company; 1983-11-23 to current/open; source msha-controller-operator-history