# Relationship history for MSHA mine 2602444

Current hierarchy: **Ronald R  Murphy → Pahrump Valley Gravel → PAHRUMP VALLEY GRAVEL, PORTABLE#**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Ronald R  Murphy → PAHRUMP VALLEY GRAVEL, PORTABLE#; 1991-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Pahrump Valley Gravel → PAHRUMP VALLEY GRAVEL, PORTABLE#; 2001-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ronald R  Murphy → Pahrump Valley Gravel; 2001-01-01 to current/open; source msha-controller-operator-history