# Relationship history for MSHA mine 4602592

Current hierarchy: **White Vincent J → I S C Inc → No 1 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

- **operator_operates_mine:** Formis Coal Co → No 1 Strip; 1950-01-01 to 1973-06-06; source msha-controller-operator-history
- **controller_controls_mine:** Dear Charles A → No 1 Strip; 1950-01-01 to 1973-06-06; source msha-controller-operator-history
- **controller_controls_operator:** Dear Charles A → Formis Coal Co; 1950-01-01 to 1973-06-06; source msha-controller-operator-history
- **operator_operates_mine:** I S C Inc → No 1 Strip; 1973-06-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** White Vincent J → No 1 Strip; 1973-06-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** White Vincent J → I S C Inc; 1973-06-07 to current/open; source msha-controller-operator-history