# Relationship history for MSHA mine 1519793

Current hierarchy: **Keith  Goggin; John A Collins → Silicon Dioxide LLC → Furnace Sand Quarry**

- 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:** Silicon Dioxide LLC → Furnace Sand Quarry; 2016-03-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John A Collins et al → Furnace Sand Quarry; 2016-03-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John A Collins et al → Silicon Dioxide LLC; 2016-03-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Keith  Goggin et al → Silicon Dioxide LLC; 2016-03-28 to current/open; source msha-controller-operator-history