# Relationship history for MSHA mine 1200758

Current hierarchy: **Sweet James Dale & Theresa Jo → Strubbe Gravel → Strubbe Gravel**

- 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:** Strubbe Gravel → Strubbe Gravel; 1950-01-01 to 1987-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Strubbe Ralph Edward & Hattie B → Strubbe Gravel; 1950-01-01 to 1987-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Strubbe Ralph Edward & Hattie B → Strubbe Gravel; 1950-01-01 to 1987-07-31; source msha-controller-operator-history
- **operator_operates_mine:** Strubbe Gravel → Strubbe Gravel; 1987-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sweet James Dale & Theresa Jo → Strubbe Gravel; 1987-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sweet James Dale & Theresa Jo → Strubbe Gravel; 1987-08-01 to current/open; source msha-controller-operator-history