# Relationship history for MSHA mine 4103726

Current hierarchy: **Sam J  Wostal → Rock Crushers Inc. → Harmel 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:** Rock Crushers Inc → Harmel Pit; 1992-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sam J  Wostal et al → Harmel Pit; 1992-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sam J  Wostal et al → Rock Crushers Inc; 1992-06-01 to current/open; source msha-controller-operator-history