# Relationship history for MSHA mine 2402481

Current hierarchy: **Ralph A  Johnsrud; Debbie S  Johnsrud → R&D Exploration & Development LLC → Banker**

- 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:** R&D Exploration & Development LLC → Banker; 2007-06-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ralph A  Johnsrud et al → Banker; 2007-06-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ralph A  Johnsrud et al → R&D Exploration & Development LLC; 2007-06-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Debbie S  Johnsrud et al → R&D Exploration & Development LLC; 2007-06-13 to current/open; source msha-controller-operator-history