# Relationship history for MSHA mine 2000741

Current hierarchy: **Edward C  Levy Jr → Burroughs Materials Corp → Holly Sand and 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:** Blount Materials Corp → Holly Sand and Gravel; 1950-01-01 to 1986-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Blount Inc → Holly Sand and Gravel; 1950-01-01 to 1986-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Blount Inc → Blount Materials Corp; 1950-01-01 to 1986-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Holly Sand & Gravel → Holly Sand and Gravel; 1986-03-01 to 2002-12-15; source msha-controller-operator-history
- **controller_controls_mine:** Edward C  Levy Jr et al → Holly Sand and Gravel; 1986-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward C  Levy Jr et al → Holly Sand & Gravel; 1986-03-01 to 2002-12-15; source msha-controller-operator-history
- **controller_controls_mine:** Edward C  Levy Jr et al → Holly Sand and Gravel; 1999-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Burroughs Materials Corp → Holly Sand and Gravel; 2002-12-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward C  Levy Jr et al → Burroughs Materials Corp; 2002-12-16 to current/open; source msha-controller-operator-history