# Relationship history for MSHA mine 3503498

Current hierarchy: **Dorothea D Ellis; Mark  Ellis → Mid-Valley Gravel Company → Mid Valley Gravel Co-Portable Crusher**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Barbara  Ellis et al → Mid Valley Gravel Co-Portable Crusher; 1950-01-01 to 2022-05-10; source msha-controller-operator-history
- **operator_operates_mine:** Mid-Valley Gravel Company → Mid Valley Gravel Co-Portable Crusher; 2000-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Barbara  Ellis et al → Mid-Valley Gravel Company; 2000-05-01 to 2022-05-10; source msha-controller-operator-history
- **controller_controls_mine:** Dorothea D Ellis et al → Mid Valley Gravel Co-Portable Crusher; 2022-05-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dorothea D Ellis et al → Mid-Valley Gravel Company; 2022-05-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark  Ellis et al → Mid-Valley Gravel Company; 2022-05-11 to current/open; source msha-controller-operator-history