# Relationship history for MSHA mine 1600350

Current hierarchy: **Mar-Low Corp → Island Sand Company Inc → Island Sand Company Incorporated**

- 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:** Island Sand Company → Island Sand Company Incorporated; 1950-01-01 to 1980-06-22; source msha-controller-operator-history
- **controller_controls_mine:** Daly W L → Island Sand Company Incorporated; 1950-01-01 to 1980-06-22; source msha-controller-operator-history
- **controller_controls_operator:** Daly W L → Island Sand Company; 1950-01-01 to 1980-06-22; source msha-controller-operator-history
- **operator_operates_mine:** Island Sand Company Inc → Island Sand Company Incorporated; 1980-06-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mar-Low Corp → Island Sand Company Incorporated; 1980-06-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mar-Low Corp → Island Sand Company Inc; 1980-06-23 to current/open; source msha-controller-operator-history