# Relationship history for MSHA mine 3000930

Current hierarchy: **Peckham Industries Inc → E. Tetz & Sons LLC → SLATE HILL 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

- **controller_controls_mine:** Edward  Tetz Jr → SLATE HILL SAND & GRAVEL; 1950-01-01 to 2023-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Helhoski Sand & Gravel Company → SLATE HILL SAND & GRAVEL; 1950-01-01 to 1979-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Sylvester V  Helhoski → SLATE HILL SAND & GRAVEL; 1950-01-01 to 1979-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Sylvester V  Helhoski → Helhoski Sand & Gravel Company; 1950-01-01 to 1979-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Slate Hill Sand & Gravel Inc → SLATE HILL SAND & GRAVEL; 1979-09-01 to 2002-08-28; source msha-controller-operator-history
- **controller_controls_mine:** Edward  Tetz Jr → SLATE HILL SAND & GRAVEL; 1979-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward  Tetz Jr → Slate Hill Sand & Gravel Inc; 1979-09-01 to 2002-08-28; source msha-controller-operator-history
- **operator_operates_mine:** E. Tetz & Sons LLC → SLATE HILL SAND & GRAVEL; 2002-08-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward  Tetz Jr → E. Tetz & Sons LLC; 2002-08-29 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Peckham Industries Inc → SLATE HILL SAND & GRAVEL; 2023-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Peckham Industries Inc → E. Tetz & Sons LLC; 2023-06-01 to current/open; source msha-controller-operator-history