# Relationship history for MSHA mine 4502614

Current hierarchy: **John D  Friend → Friend & Rikalo Inc → PORTABLE CRUSHER #1**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Friend & Rikalo Inc → PORTABLE CRUSHER #1; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John D  Friend et al → PORTABLE CRUSHER #1; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John D  Friend et al → Friend & Rikalo Inc; 1979-01-01 to current/open; source msha-controller-operator-history