# Relationship history for MSHA mine 0405802

Current hierarchy: **Dave  Beck → QUALITY AGGREGATES INC. → PORTABLE PLANT #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:** Aggtech, Inc. → PORTABLE PLANT #1; 2010-04-26 to 2017-05-21; source msha-controller-operator-history
- **controller_controls_mine:** Stan  Houck → PORTABLE PLANT #1; 2010-04-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stan  Houck → Aggtech, Inc.; 2010-04-26 to 2017-05-21; source msha-controller-operator-history
- **operator_operates_mine:** QUALITY AGGREGATES INC. → PORTABLE PLANT #1; 2017-05-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dave  Beck → PORTABLE PLANT #1; 2017-05-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dave  Beck → QUALITY AGGREGATES INC.; 2017-05-22 to current/open; source msha-controller-operator-history