# Relationship history for MSHA mine 4800070

Current hierarchy: **Halliburton Company → Bentonite Performance Minerals, LLC → BPM Colony 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:** Baroid Drilling Fluids Inc → BPM Colony Mill; 1950-01-01 to 1991-11-17; source msha-controller-operator-history
- **controller_controls_mine:** Nl Industries Inc → BPM Colony Mill; 1950-01-01 to 1996-03-04; source msha-controller-operator-history
- **controller_controls_operator:** Nl Industries Inc → Baroid Drilling Fluids Inc; 1950-01-01 to 1991-11-17; source msha-controller-operator-history
- **operator_operates_mine:** Bentonite Corp → BPM Colony Mill; 1991-11-18 to 1994-01-20; source msha-controller-operator-history
- **controller_controls_mine:** Tremont → BPM Colony Mill; 1991-11-18 to 1994-01-20; source msha-controller-operator-history
- **controller_controls_operator:** Tremont → Bentonite Corp; 1991-11-18 to 1994-01-20; source msha-controller-operator-history
- **operator_operates_mine:** Bentonite Corp → BPM Colony Mill; 1994-01-21 to 1998-02-25; source msha-controller-operator-history
- **controller_controls_mine:** Dresser Industries Inc → BPM Colony Mill; 1994-01-21 to 1998-02-25; source msha-controller-operator-history
- **controller_controls_operator:** Dresser Industries Inc → Bentonite Corp; 1994-01-21 to 1998-02-25; source msha-controller-operator-history
- **operator_operates_mine:** Bentonite Performance Minerals, LLC → BPM Colony Mill; 1998-02-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Halliburton Company → BPM Colony Mill; 1998-02-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Halliburton Company → Bentonite Performance Minerals, LLC; 1998-02-26 to current/open; source msha-controller-operator-history