# Relationship history for MSHA mine 1101040

Current hierarchy: **Mc Gurk Betty A → Bohac'S Sand Pit → Bohac Sand Pit**

- 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:** Bohac & Son → Bohac Sand Pit; 1950-01-01 to 1986-01-26; source msha-controller-operator-history
- **controller_controls_mine:** Bohac Florence → Bohac Sand Pit; 1950-01-01 to 1986-01-26; source msha-controller-operator-history
- **controller_controls_operator:** Bohac Florence → Bohac & Son; 1950-01-01 to 1986-01-26; source msha-controller-operator-history
- **operator_operates_mine:** Bohac'S Sand Pit → Bohac Sand Pit; 1986-01-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mc Gurk Betty A → Bohac Sand Pit; 1986-01-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Gurk Betty A → Bohac'S Sand Pit; 1986-01-27 to current/open; source msha-controller-operator-history