# Relationship history for MSHA mine 1102898

Current hierarchy: **James S  Toyan; Jeff B  Thurlwell → Spring Lake Sand & Gravel → Spring Lake 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:** Spring Lake Sand & Gravel → Spring Lake Sand & Gravel; 1990-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James S  Toyan et al → Spring Lake Sand & Gravel; 1990-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James S  Toyan et al → Spring Lake Sand & Gravel; 1990-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jeff B  Thurlwell et al → Spring Lake Sand & Gravel; 1990-06-01 to current/open; source msha-controller-operator-history