# Relationship history for MSHA mine 4602013

Current hierarchy: **Cline Deborah → Debby Coal Company → No 2 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Debbie Coal Company → No 2 Mine; 1950-01-01 to 1973-02-21; source msha-controller-operator-history
- **controller_controls_mine:** Robert  Day → No 2 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Day → Debbie Coal Company; 1950-01-01 to 1973-02-21; source msha-controller-operator-history
- **operator_operates_mine:** C & E Coal Company → No 2 Mine; 1973-02-22 to 1974-01-10; source msha-controller-operator-history
- **controller_controls_mine:** C & E Coal Co → No 2 Mine; 1973-02-22 to 1974-01-10; source msha-controller-operator-history
- **controller_controls_operator:** C & E Coal Co → C & E Coal Company; 1973-02-22 to 1974-01-10; source msha-controller-operator-history
- **operator_operates_mine:** Arizona Fuel Company Inc → No 2 Mine; 1974-01-11 to 1975-06-27; source msha-controller-operator-history
- **controller_controls_mine:** Arizona Fuel Co Inc → No 2 Mine; 1974-01-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Arizona Fuel Co Inc → Arizona Fuel Company Inc; 1974-01-11 to 1975-06-27; source msha-controller-operator-history
- **controller_controls_mine:** Cline Deborah → No 2 Mine; 1975-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Debby Coal Company → No 2 Mine; 1975-06-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cline Deborah → Debby Coal Company; 1975-06-28 to current/open; source msha-controller-operator-history