# Relationship history for MSHA mine 0504750

Current hierarchy: **Randall  Robins; Lou Ann  Robins → Robins Construction → Robins 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:** Robins Construction → Robins Portable; 2002-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lou Ann  Robins et al → Robins Portable; 2002-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lou Ann  Robins et al → Robins Construction; 2002-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Randall  Robins et al → Robins Construction; 2002-06-18 to current/open; source msha-controller-operator-history