# Relationship history for MSHA mine 3901523

Current hierarchy: **Marshall  Johnson → Johnson Digging → Johnson 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:** Johnson Digging → Johnson Pit; 2008-05-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Marshall  Johnson → Johnson Pit; 2008-05-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Marshall  Johnson → Johnson Digging; 2008-05-22 to current/open; source msha-controller-operator-history