# Relationship history for MSHA mine 4607754

Current hierarchy: **Marcum Willis → Willis Marcum Trucking Company → Refuse Reprocessing Area**

- 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:** Willis Marcum Trucking Company → Refuse Reprocessing Area; 1989-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Marcum Willis → Refuse Reprocessing Area; 1989-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Marcum Willis → Willis Marcum Trucking Company; 1989-08-01 to current/open; source msha-controller-operator-history