# Relationship history for MSHA mine 3003328

Current hierarchy: **George  Rifenburg; John K  Rifenburg → Rifenburg Construction Inc → #50208**

- 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:** John K  Rifenburg et al → #50208; 1990-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Rifenburg Construction Inc → #50208; 2000-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John K  Rifenburg et al → Rifenburg Construction Inc; 2000-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** George  Rifenburg et al → Rifenburg Construction Inc; 2000-05-01 to current/open; source msha-controller-operator-history