# Relationship history for MSHA mine 4202714

Current hierarchy: **Ryan G  Rees → Harward and Rees → Portable Plant 2**

- 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

- **controller_controls_mine:** Ryan G  Rees → Portable Plant 2; 2017-04-28 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Harward and Rees → Portable Plant 2; 2020-07-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ryan G  Rees → Harward and Rees; 2020-07-07 to current/open; source msha-controller-operator-history