# Relationship history for MSHA mine 3602854

Current hierarchy: **Rochester & Pittsburgh Coal Company → Kent Coal Mining Company → Iselin No 6 No 9 No 10 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Helad Coal Company Inc → Iselin No 6 No 9 No 10 Surface; 1950-01-01 to 1980-01-08; source msha-controller-operator-history
- **controller_controls_mine:** Davis Adrian D → Iselin No 6 No 9 No 10 Surface; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Davis Adrian D → Helad Coal Company Inc; 1950-01-01 to 1980-01-08; source msha-controller-operator-history
- **controller_controls_mine:** Rochester & Pittsburgh Coal Company → Iselin No 6 No 9 No 10 Surface; 1978-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Kent Coal Mining Company → Iselin No 6 No 9 No 10 Surface; 1980-01-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rochester & Pittsburgh Coal Company → Kent Coal Mining Company; 1980-01-09 to current/open; source msha-controller-operator-history