# Relationship history for MSHA mine 2900477

Current hierarchy: **Estate of Juanita E Medina → Robert Medina & Sons → Martinez Pit & Plant**

- 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:** Robert Medina & Sons → Martinez Pit & Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Estate of Juanita E Medina → Martinez Pit & Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Estate of Juanita E Medina → Robert Medina & Sons; 1950-01-01 to current/open; source msha-controller-operator-history