# Relationship history for MSHA mine 4502404

Current hierarchy: **Farris Robert C → Lopez Ready Mix → Lopez Ready Mix 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Lopez Ready-Mix → Lopez Ready Mix Pit & Plant; 1950-01-01 to 1987-03-16; source msha-controller-operator-history
- **controller_controls_mine:** Pickering Richard L → Lopez Ready Mix Pit & Plant; 1950-01-01 to 1987-03-16; source msha-controller-operator-history
- **controller_controls_operator:** Pickering Richard L → Lopez Ready-Mix; 1950-01-01 to 1987-03-16; source msha-controller-operator-history
- **operator_operates_mine:** Lopez Ready Mix → Lopez Ready Mix Pit & Plant; 1987-03-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Farris Robert C → Lopez Ready Mix Pit & Plant; 1987-03-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Farris Robert C → Lopez Ready Mix; 1987-03-17 to current/open; source msha-controller-operator-history