# Relationship history for MSHA mine 3003075

Current hierarchy: **Karen  Lietz → K & D Gravel Products Company → 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

- **controller_controls_mine:** Karen  Lietz → PORTABLE PLANT #1; 1985-04-24 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** K & D Gravel Products Company → PORTABLE PLANT #1; 1992-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Karen  Lietz → K & D Gravel Products Company; 1992-10-01 to current/open; source msha-controller-operator-history