# Relationship history for MSHA mine 4603457

Current hierarchy: **Phillips Robert L → Branch Coal Inc → No 1 Mine**

- 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:** Nichols Coal Company → No 1 Mine; 1950-01-01 to 1974-09-14; source msha-controller-operator-history
- **controller_controls_mine:** Nichols Henry → No 1 Mine; 1950-01-01 to 1974-09-14; source msha-controller-operator-history
- **controller_controls_operator:** Nichols Henry → Nichols Coal Company; 1950-01-01 to 1974-09-14; source msha-controller-operator-history
- **operator_operates_mine:** V & E Coal Company → No 1 Mine; 1974-09-15 to 1975-03-21; source msha-controller-operator-history
- **controller_controls_mine:** Morgan Oscar → No 1 Mine; 1974-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Morgan Oscar → V & E Coal Company; 1974-09-15 to 1975-03-21; source msha-controller-operator-history
- **operator_operates_mine:** Sabrina Sean Coal Company → No 1 Mine; 1975-03-22 to 1977-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Blankenship Clarence → No 1 Mine; 1975-03-22 to 1977-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Blankenship Clarence → Sabrina Sean Coal Company; 1975-03-22 to 1977-01-31; source msha-controller-operator-history
- **operator_operates_mine:** Branch Coal Inc → No 1 Mine; 1977-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Phillips Robert L → No 1 Mine; 1977-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Phillips Robert L → Branch Coal Inc; 1977-02-01 to current/open; source msha-controller-operator-history