# Relationship history for MSHA mine 2700266

Current hierarchy: **Steven  Lenzi → P & S Sand & Gravel → P&S SAND & GRAVEL**

- 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:** Barrington Sand & Gravel Inc → P&S SAND & GRAVEL; 1987-03-01 to 1993-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Richard  Hebbard → P&S SAND & GRAVEL; 1987-03-01 to 1993-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Hebbard → Barrington Sand & Gravel Inc; 1987-03-01 to 1993-04-30; source msha-controller-operator-history
- **operator_operates_mine:** P & S Sand & Gravel → P&S SAND & GRAVEL; 1993-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Steven  Lenzi → P&S SAND & GRAVEL; 1993-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steven  Lenzi → P & S Sand & Gravel; 1993-05-01 to current/open; source msha-controller-operator-history