# Relationship history for MSHA mine 2600412

Current hierarchy: **Halliburton Company → Halliburton Energy Services, Inc. → DUNPHY 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 → DUNPHY MILL; 1950-01-01 to 1990-06-04; source msha-controller-operator-history
- **controller_controls_mine:** Nl Industries Inc → DUNPHY 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 1990-06-04; source msha-controller-operator-history
- **operator_operates_mine:** Mine Service & Supply Company Inc → DUNPHY MILL; 1990-06-05 to 2002-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Terral G  Young → DUNPHY MILL; 1990-06-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Terral G  Young → Mine Service & Supply Company Inc; 1990-06-05 to 2002-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Halliburton Company → DUNPHY MILL; 1998-02-26 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Halliburton Energy Services, Inc. → DUNPHY MILL; 2002-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Halliburton Company → Halliburton Energy Services, Inc.; 2002-04-01 to current/open; source msha-controller-operator-history