# Relationship history for MSHA mine 3607227

Current hierarchy: **Joseph  Kleeman → Ashland Coal Company → Preparation 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:** Ashland Coal Company → Preparation Plant; 1981-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Joseph  Kleeman  et al → Preparation Plant; 1981-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joseph  Kleeman  et al → Ashland Coal Company; 1981-10-01 to current/open; source msha-controller-operator-history