# Relationship history for MSHA mine 2902469

Current hierarchy: **GMS Inc; David  Shoup → United Materials, LLP → IROCK TS 620 SCREEN**

- 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:** David  Shoup et al → IROCK TS 620 SCREEN; 2015-05-08 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** United Materials, LLP → IROCK TS 620 SCREEN; 2017-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David  Shoup et al → United Materials, LLP; 2017-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** GMS Inc et al → United Materials, LLP; 2017-02-01 to current/open; source msha-controller-operator-history