# Relationship history for MSHA mine 2003095

Current hierarchy: **Andrew  Schmidt → Quality Excavating & Equipment Leasing → Portable Eljay 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Quality Excavating → Portable Eljay Plant; 1998-06-01 to 2003-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Fred  Birnbaum et al → Portable Eljay Plant; 1998-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Fred  Birnbaum et al → Quality Excavating; 1998-06-01 to 2003-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Quality Excavating & Equipment Leasing → Portable Eljay Plant; 2003-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Andrew  Schmidt → Portable Eljay Plant; 2003-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Andrew  Schmidt → Quality Excavating & Equipment Leasing; 2003-05-01 to current/open; source msha-controller-operator-history