# Relationship history for MSHA mine 0901164

Current hierarchy: **Wilks Brothers LLC → Carbo Ceramics Inc. → Toomsboro**

- 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:** Gary A  Kolstad et al → Toomsboro; 1987-06-30 to 2020-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Carbo Ceramics Inc. → Toomsboro; 2005-11-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gary A  Kolstad et al → Carbo Ceramics Inc.; 2005-11-22 to 2020-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Wilks Brothers LLC → Toomsboro; 2020-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wilks Brothers LLC → Carbo Ceramics Inc.; 2020-07-01 to current/open; source msha-controller-operator-history