# Relationship history for MSHA mine 2602047

Current hierarchy: **Powers Georgia → Southern Nevada Crushing → Nevada Gypsum & Mining**

- 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:** Off Road Enterprises → Nevada Gypsum & Mining; 1988-02-01 to 1989-05-19; source msha-controller-operator-history
- **controller_controls_mine:** Barlow Doug & Lou → Nevada Gypsum & Mining; 1988-02-01 to 1989-05-19; source msha-controller-operator-history
- **controller_controls_operator:** Barlow Doug & Lou → Off Road Enterprises; 1988-02-01 to 1989-05-19; source msha-controller-operator-history
- **operator_operates_mine:** Southern Nevada Crushing → Nevada Gypsum & Mining; 1989-05-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Powers Georgia → Nevada Gypsum & Mining; 1989-05-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Powers Georgia → Southern Nevada Crushing; 1989-05-20 to current/open; source msha-controller-operator-history