# Relationship history for MSHA mine 2003541

Current hierarchy: **Edward C  Levy Jr → Burroughs Materials Corp. → Groveland 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Edward C  Levy Jr et al → Groveland Sand & Gravel; 1999-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Burroughs Materials Corp. → Groveland Sand & Gravel; 2017-03-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward C  Levy Jr et al → Burroughs Materials Corp.; 2017-03-24 to current/open; source msha-controller-operator-history