# Relationship history for MSHA mine 3304374

Current hierarchy: **Horizon Natural Resources Incorporated → R & F Coal Company → Rice #10 (Strip)**

- 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:** Zeigler Coal Holding Company → Rice #10 (Strip); 1992-11-16 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** R & F Coal Company → Rice #10 (Strip); 1996-04-01 to 1998-09-01; source msha-controller-operator-history
- **controller_controls_operator:** Zeigler Coal Holding Company → R & F Coal Company; 1996-04-01 to 1998-09-01; source msha-controller-operator-history
- **operator_operates_mine:** R & F Coal Company → Rice #10 (Strip); 1998-09-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Horizon Natural Resources Incorporated → Rice #10 (Strip); 1998-09-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Horizon Natural Resources Incorporated → R & F Coal Company; 1998-09-02 to current/open; source msha-controller-operator-history