# Relationship history for MSHA mine 1200642

Current hierarchy: **Paul R  Chael; Glenda M  Snyder; Greg  Thomas → Crisman Sand Company Inc → No 1**

- 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:** Crisman Sand Company Inc → No 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Edward P  Nicholson → No 1; 1950-01-01 to 2020-10-06; source msha-controller-operator-history
- **controller_controls_operator:** Edward P  Nicholson → Crisman Sand Company Inc; 1950-01-01 to 2020-10-06; source msha-controller-operator-history
- **controller_controls_mine:** Glenda M  Snyder et al → No 1; 2020-10-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Glenda M  Snyder et al → Crisman Sand Company Inc; 2020-10-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Paul R  Chael et al → Crisman Sand Company Inc; 2020-10-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Greg  Thomas et al → Crisman Sand Company Inc; 2020-10-07 to current/open; source msha-controller-operator-history