# Relationship history for MSHA mine 3610227

Current hierarchy: **Debbie  Schell; Barry  Schell → Schell Building and Landscaping Stone Inc. → Schell Quarry**

- 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:** Schell Building and Landscaping Stone Inc. → Schell Quarry; 2018-02-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Debbie  Schell et al → Schell Quarry; 2018-02-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Debbie  Schell et al → Schell Building and Landscaping Stone Inc.; 2018-02-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Barry  Schell et al → Schell Building and Landscaping Stone Inc.; 2018-02-22 to current/open; source msha-controller-operator-history