# Relationship history for MSHA mine 2103899

Current hierarchy: **Trent  Duda → Earthwork Services Inc → Cha-Ching Screen Plant**

- 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:** Earthwork Services Inc → Cha-Ching Screen Plant; 2017-02-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Trent  Duda → Cha-Ching Screen Plant; 2017-02-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Trent  Duda → Earthwork Services Inc; 2017-02-14 to current/open; source msha-controller-operator-history