# Relationship history for MSHA mine 3700212

Current hierarchy: **Robert A Pezza; Michael T Pezza → Material Sand & Stone Corp → Pound Hill Quarry**

- 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

- **controller_controls_mine:** Robert  A  Pezza → Pound Hill Quarry; 1994-09-23 to 2016-05-23; source msha-controller-operator-history
- **operator_operates_mine:** Material Sand & Stone Corp → Pound Hill Quarry; 2011-03-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert  A  Pezza → Material Sand & Stone Corp; 2011-03-29 to 2016-05-23; source msha-controller-operator-history
- **controller_controls_mine:** Michael T Pezza → Pound Hill Quarry; 2016-05-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael T Pezza → Material Sand & Stone Corp; 2016-05-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert A Pezza → Material Sand & Stone Corp; 2016-05-24 to current/open; source msha-controller-operator-history