# Relationship history for MSHA mine 4503516

Current hierarchy: **DOUG  HOFFMAN; SUE  HOFFMAN → D & R Excavating Inc → Portable #1**

- 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:** D & R Excavating Inc → Portable #1; 2002-08-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** DOUG  HOFFMAN  ET AL → Portable #1; 2002-08-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** DOUG  HOFFMAN  ET AL → D & R Excavating Inc; 2002-08-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** SUE  HOFFMAN  ET AL → D & R Excavating Inc; 2002-08-08 to current/open; source msha-controller-operator-history