# Relationship history for MSHA mine 1202346

Current hierarchy: **Michael  Marburger; Willis  Marburger → Malea Farm → Malea Sand & Gravel**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Malea Farm → Malea Sand & Gravel; 2003-04-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Willis  Marburger et al → Malea Sand & Gravel; 2003-04-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Willis  Marburger et al → Malea Farm; 2003-04-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Marburger et al → Malea Farm; 2003-04-15 to current/open; source msha-controller-operator-history