# Relationship history for MSHA mine 4202648

Current hierarchy: **Blake  Demille → Rocky Ridge Rock → RR 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Rocky Ridge Rock → RR Portable; 2015-07-29 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Blake  Demille → RR Portable; 2015-07-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blake  Demille → Rocky Ridge Rock; 2015-07-29 to current/open; source msha-controller-operator-history