# Relationship history for MSHA mine 1700321

Current hierarchy: **William  Del Monaco Jr; Chris  Del Monaco → Thomas De Cenzo Inc → PORTABLE 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:** Thomas De Cenzo Inc → PORTABLE PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Chris  Del Monaco  et al → PORTABLE PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chris  Del Monaco  et al → Thomas De Cenzo Inc; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William  Del Monaco Jr  et al → Thomas De Cenzo Inc; 1950-01-01 to current/open; source msha-controller-operator-history