# Relationship history for MSHA mine 1900573

Current hierarchy: **Beverly F Nawrocki → NAWROCKI CONSTRUCTION INC → LYONS STREET PIT & MILL**

- 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:** Nawrocki Construction Inc → LYONS STREET PIT & MILL; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Beverly F Nawrocki → LYONS STREET PIT & MILL; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Beverly F Nawrocki → Nawrocki Construction Inc; 1950-01-01 to current/open; source msha-controller-operator-history