# Relationship history for MSHA mine 3609687

Current hierarchy: **Mary G  Lever → Susquehanna Haul & Drilling LLC → Dogtown Coal Refuse Site**

- 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:** Susquehanna Haul & Drilling LLC → Dogtown Coal Refuse Site; 2009-03-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mary G  Lever et al → Dogtown Coal Refuse Site; 2009-03-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mary G  Lever et al → Susquehanna Haul & Drilling LLC; 2009-03-23 to current/open; source msha-controller-operator-history