# Relationship history for MSHA mine 3606461

Current hierarchy: **Harner Roy E & Delbert L Artz → A & H Coal Company → No 2 Slope**

- 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:** Harner Roy E & Delbert L Artz → No 2 Slope; 1974-08-02 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** A & H Coal Company → No 2 Slope; 1977-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harner Roy E & Delbert L Artz → A & H Coal Company; 1977-07-01 to current/open; source msha-controller-operator-history