# Relationship history for MSHA mine 1517699

Current hierarchy: **Progress Energy Inc → Powell Mountain Coal Co., Inc. → Limestone Refuse Fill**

- 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:** Amvest Corporation → Limestone Refuse Fill; 1991-11-20 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Kentucky Darby Coal Company → Limestone Refuse Fill; 1995-08-01 to 2004-06-17; source msha-controller-operator-history
- **controller_controls_operator:** Amvest Corporation → Kentucky Darby Coal Company; 1995-08-01 to 2004-06-17; source msha-controller-operator-history
- **controller_controls_mine:** Progress Energy Inc → Limestone Refuse Fill; 2000-11-30 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Powell Mountain Coal Co., Inc. → Limestone Refuse Fill; 2004-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Progress Energy Inc → Powell Mountain Coal Co., Inc.; 2004-06-18 to current/open; source msha-controller-operator-history