# Relationship history for MSHA mine 0100713

Current hierarchy: **Alfred Mc Alpine Inc → R & S Materials Inc → Silica Ii**

- 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:** Alabama Silica Company Inc → Silica Ii; 1950-01-01 to 1985-02-05; source msha-controller-operator-history
- **controller_controls_mine:** K R  Maddox  et al → Silica Ii; 1950-01-01 to 1985-02-05; source msha-controller-operator-history
- **controller_controls_operator:** K R  Maddox  et al → Alabama Silica Company Inc; 1950-01-01 to 1985-02-05; source msha-controller-operator-history
- **operator_operates_mine:** R & S Materials Inc → Silica Ii; 1985-02-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Alfred Mc Alpine Inc → Silica Ii; 1985-02-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alfred Mc Alpine Inc → R & S Materials Inc; 1985-02-06 to current/open; source msha-controller-operator-history