# Relationship history for MSHA mine 2302347

Current hierarchy: **Bobby  Pierce → Pierce Sand → Pierce Sand Gilford**

- 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

- **controller_controls_mine:** Bobby  Pierce → Pierce Sand Gilford; 1992-06-03 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Pierce Sand → Pierce Sand Gilford; 2006-10-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bobby  Pierce → Pierce Sand; 2006-10-13 to current/open; source msha-controller-operator-history