# Relationship history for MSHA mine 4503392

Current hierarchy: **Ernest L  Simmons; Robin  Simmons → Simmons & Son Hauling → Eagle Rock 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:** Simmons & Son Hauling → Eagle Rock Pit; 1999-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ernest L  Simmons et al → Eagle Rock Pit; 1999-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ernest L  Simmons et al → Simmons & Son Hauling; 1999-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robin  Simmons et al → Simmons & Son Hauling; 1999-04-01 to current/open; source msha-controller-operator-history