# Relationship history for MSHA mine 3607269

Current hierarchy: **Darryl  Koperna → H L & W Coal Company → H L & W Coal Company**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Potts Contracting Company Inc → H L & W Coal Company; 1982-02-01 to 1988-12-29; source msha-controller-operator-history
- **controller_controls_mine:** Potts Allen L → H L & W Coal Company; 1982-02-01 to 1993-01-07; source msha-controller-operator-history
- **controller_controls_operator:** Potts Allen L → Potts Contracting Company Inc; 1982-02-01 to 1988-12-29; source msha-controller-operator-history
- **controller_controls_mine:** Lehman Marlin D Jr-Adam Haldeman Et Al → H L & W Coal Company; 1986-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** H L & W Coal Company → H L & W Coal Company; 1988-12-30 to 1999-01-01; source msha-controller-operator-history
- **controller_controls_operator:** Lehman Marlin D Jr-Adam Haldeman Et Al → H L & W Coal Company; 1988-12-30 to 1999-01-01; source msha-controller-operator-history
- **operator_operates_mine:** H L & W Coal Company → H L & W Coal Company; 1999-01-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Darryl  Koperna → H L & W Coal Company; 1999-01-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Darryl  Koperna → H L & W Coal Company; 1999-01-02 to current/open; source msha-controller-operator-history