# Relationship history for MSHA mine 1900644

Current hierarchy: **D P C Enterprises Inc → Valley Aggregates Corp → TURKEY 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

- **operator_operates_mine:** Wzorek Sand & Gravel Corp → TURKEY HILL QUARRY; 1950-01-01 to 1986-03-30; source msha-controller-operator-history
- **controller_controls_mine:** James F  Wzorek → TURKEY HILL QUARRY; 1950-01-01 to 1986-03-30; source msha-controller-operator-history
- **controller_controls_operator:** James F  Wzorek → Wzorek Sand & Gravel Corp; 1950-01-01 to 1986-03-30; source msha-controller-operator-history
- **operator_operates_mine:** Valley Aggregates Corp → TURKEY HILL QUARRY; 1986-03-31 to 1987-02-11; source msha-controller-operator-history
- **controller_controls_mine:** Wzorek James F Jr → TURKEY HILL QUARRY; 1986-03-31 to 1987-02-11; source msha-controller-operator-history
- **controller_controls_operator:** Wzorek James F Jr → Valley Aggregates Corp; 1986-03-31 to 1987-02-11; source msha-controller-operator-history
- **operator_operates_mine:** Valley Aggregates Corp → TURKEY HILL QUARRY; 1987-02-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** D P C Enterprises Inc → TURKEY HILL QUARRY; 1987-02-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** D P C Enterprises Inc → Valley Aggregates Corp; 1987-02-12 to current/open; source msha-controller-operator-history