# Relationship history for MSHA mine 4102760

Current hierarchy: **Baker Hughes Inc → Milpark Drilling Fluids → Galveston Grinding Plant**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Milchem Inc → Galveston Grinding Plant; 1950-01-01 to 1985-11-22; source msha-controller-operator-history
- **controller_controls_mine:** Baker Hughes Inc → Galveston Grinding Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Baker Hughes Inc → Milchem Inc; 1950-01-01 to 1985-11-22; source msha-controller-operator-history
- **controller_controls_mine:** Baker Hughes Inc → Galveston Grinding Plant; 1980-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Milpark → Galveston Grinding Plant; 1985-11-23 to 1986-12-09; source msha-controller-operator-history
- **controller_controls_mine:** Baker-Hughes Inc & Newpark Resources Inc → Galveston Grinding Plant; 1985-11-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Baker-Hughes Inc & Newpark Resources Inc → Milpark; 1985-11-23 to 1986-12-09; source msha-controller-operator-history
- **operator_operates_mine:** Milpark Drilling Fluids → Galveston Grinding Plant; 1986-12-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Baker Hughes Inc → Milpark Drilling Fluids; 1986-12-10 to current/open; source msha-controller-operator-history