# Relationship history for MSHA mine 4801475

Current hierarchy: **Harvest Holdings II LLC → Black Hills Lignite A Limited Liability Co → GLENROCK MILL**

- 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:** Black Hills Lignite A Limited Liability Co → GLENROCK MILL; 1987-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thomas A  Thorson et al → GLENROCK MILL; 1987-08-01 to 2020-01-16; source msha-controller-operator-history
- **controller_controls_operator:** Thomas A  Thorson et al → Black Hills Lignite A Limited Liability Co; 1987-08-01 to 2020-01-16; source msha-controller-operator-history
- **controller_controls_mine:** Michael  Farmar et al → GLENROCK MILL; 2020-01-17 to 2025-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Farmar et al → Black Hills Lignite A Limited Liability Co; 2020-01-17 to 2025-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Brad  Knickel et al → Black Hills Lignite A Limited Liability Co; 2020-01-17 to 2025-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Harvest Holdings II LLC → GLENROCK MILL; 2025-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harvest Holdings II LLC → Black Hills Lignite A Limited Liability Co; 2025-07-01 to current/open; source msha-controller-operator-history