# Relationship history for MSHA mine 4202153

Current hierarchy: **Kenneth L  Seng → Kenny Seng Construction, Inc → Portable, Crushing Plant/AMI Thunderbird**

- 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:** Kenneth L  Seng → Portable, Crushing Plant/AMI Thunderbird; 1996-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Kenny Seng Construction, Inc → Portable, Crushing Plant/AMI Thunderbird; 1996-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kenneth L  Seng → Kenny Seng Construction, Inc; 1996-08-01 to current/open; source msha-controller-operator-history