# Relationship history for MSHA mine 0404067

Current hierarchy: **Robert S  Bowen → Drake Materials Inc → DRAKE MATERIALS**

- 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:** Drake Sand & Gravel → DRAKE MATERIALS; 1950-01-01 to 1996-11-19; source msha-controller-operator-history
- **controller_controls_mine:** Ken  Drake → DRAKE MATERIALS; 1950-01-01 to 1996-11-19; source msha-controller-operator-history
- **controller_controls_operator:** Ken  Drake → Drake Sand & Gravel; 1950-01-01 to 1996-11-19; source msha-controller-operator-history
- **operator_operates_mine:** Drake Materials Inc → DRAKE MATERIALS; 1996-11-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert S  Bowen → DRAKE MATERIALS; 1996-11-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert S  Bowen → Drake Materials Inc; 1996-11-20 to current/open; source msha-controller-operator-history