# Relationship history for MSHA mine 4102510

Current hierarchy: **Wanda S  Kersh → Bell Sand Company Inc. → Bell Sand Company Inc.**

- 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:** Bell Sand Company Inc. → Bell Sand Company Inc.; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** R E  Kersh → Bell Sand Company Inc.; 1950-01-01 to 2016-01-04; source msha-controller-operator-history
- **controller_controls_operator:** R E  Kersh → Bell Sand Company Inc.; 1950-01-01 to 2016-01-04; source msha-controller-operator-history
- **controller_controls_mine:** Wanda S  Kersh → Bell Sand Company Inc.; 2016-01-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wanda S  Kersh → Bell Sand Company Inc.; 2016-01-05 to current/open; source msha-controller-operator-history