# Relationship history for MSHA mine 1515968

Current hierarchy: **Hicks Paul L → Blue Cat Sand Company Inc → #1**

- 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:** Blue Cat Sand Company Inc → #1; 1987-03-01 to 1987-07-13; source msha-controller-operator-history
- **controller_controls_mine:** Friend Kathy Lou → #1; 1987-03-01 to 1987-07-13; source msha-controller-operator-history
- **controller_controls_operator:** Friend Kathy Lou → Blue Cat Sand Company Inc; 1987-03-01 to 1987-07-13; source msha-controller-operator-history
- **operator_operates_mine:** Blue Cat Sand Company Inc → #1; 1987-07-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hicks Paul L → #1; 1987-07-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hicks Paul L → Blue Cat Sand Company Inc; 1987-07-14 to current/open; source msha-controller-operator-history