# Relationship history for MSHA mine 3901536

Current hierarchy: **Duane C  Pankratz → Sandman Products → Cliff #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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Sandman Products → Cliff #1; 2009-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Duane C  Pankratz → Cliff #1; 2009-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Duane C  Pankratz → Sandman Products; 2009-03-09 to current/open; source msha-controller-operator-history