# Relationship history for MSHA mine 3304260

Current hierarchy: **Kristen  Kalis; Michael  Lansberry → X L Sand and Gravel Co Inc → X L Sand and Gravel Co 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** X L Sand and Gravel Co Inc → X L Sand and Gravel Co Inc; 1992-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Raymond A  Lansberry → X L Sand and Gravel Co Inc; 1992-02-01 to 2012-01-08; source msha-controller-operator-history
- **controller_controls_operator:** Raymond A  Lansberry → X L Sand and Gravel Co Inc; 1992-02-01 to 2012-01-08; source msha-controller-operator-history
- **controller_controls_mine:** Kristen  Kalis et al → X L Sand and Gravel Co Inc; 2012-01-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kristen  Kalis et al → X L Sand and Gravel Co Inc; 2012-01-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Lansberry et al → X L Sand and Gravel Co Inc; 2012-01-09 to current/open; source msha-controller-operator-history