# Relationship history for MSHA mine 4103391

Current hierarchy: **George Grady → George Ready Mix Inc → Palo Alto Pit**

- 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

- **controller_controls_mine:** Joe R  Williams Jr → Palo Alto Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Texas Architectural Aggregate Inc → Palo Alto Pit; 1986-03-01 to 1989-01-11; source msha-controller-operator-history
- **controller_controls_operator:** Joe R  Williams Jr → Texas Architectural Aggregate Inc; 1986-03-01 to 1989-01-11; source msha-controller-operator-history
- **operator_operates_mine:** George Ready Mix Inc → Palo Alto Pit; 1989-01-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** George Grady → Palo Alto Pit; 1989-01-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** George Grady → George Ready Mix Inc; 1989-01-12 to current/open; source msha-controller-operator-history