# Relationship history for MSHA mine 0505053

Current hierarchy: **Rick  Miller; Fredrick  Miller → Laser Oilfield Services → Portable Plant 3**

- 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:** Rick  Miller et al → Portable Plant 3; 2012-07-20 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Laser Oilfield Services → Portable Plant 3; 2015-11-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rick  Miller et al → Laser Oilfield Services; 2015-11-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Fredrick  Miller et al → Laser Oilfield Services; 2015-11-05 to current/open; source msha-controller-operator-history