# Relationship history for MSHA mine 1601261

Current hierarchy: **Bobby G  Johnson → Industrial Gravel Contractors → PIT #2**

- 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

- **controller_controls_mine:** Bobby G  Johnson → PIT #2; 1988-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Industrial Gravel Contractors → PIT #2; 1993-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bobby G  Johnson → Industrial Gravel Contractors; 1993-06-01 to current/open; source msha-controller-operator-history