# Relationship history for MSHA mine 2002376

Current hierarchy: **Charlotte & Roy Myers → Myers Sand & Gravel → Myers 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

- **operator_operates_mine:** Lake Sand & Gravel → Myers Sand & Gravel; 1950-01-01 to 1980-07-01; source msha-controller-operator-history
- **controller_controls_mine:** Nezwik Ronald E-David J Horowski & Robert Carey → Myers Sand & Gravel; 1950-01-01 to 1980-07-01; source msha-controller-operator-history
- **controller_controls_operator:** Nezwik Ronald E-David J Horowski & Robert Carey → Lake Sand & Gravel; 1950-01-01 to 1980-07-01; source msha-controller-operator-history
- **operator_operates_mine:** E R S Inc Sand & Gravel → Myers Sand & Gravel; 1980-07-02 to 1993-05-05; source msha-controller-operator-history
- **controller_controls_mine:** Van Dam Ernest D → Myers Sand & Gravel; 1980-07-02 to 1993-05-05; source msha-controller-operator-history
- **controller_controls_operator:** Van Dam Ernest D → E R S Inc Sand & Gravel; 1980-07-02 to 1993-05-05; source msha-controller-operator-history
- **operator_operates_mine:** Myers Sand & Gravel → Myers Sand & Gravel; 1993-05-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Charlotte & Roy Myers → Myers Sand & Gravel; 1993-05-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Charlotte & Roy Myers → Myers Sand & Gravel; 1993-05-06 to current/open; source msha-controller-operator-history