# Relationship history for MSHA mine 3402110

Current hierarchy: **Cheryl Christine  Taylor; Leah Renee  Johnson; Roberta Carol  Gayler → Black Mesa Sand, LLC → Black Mesa Sand**

- 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:** Black Mesa Sand, LLC → Black Mesa Sand; 2010-08-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Roberta Carol  Gayler et al → Black Mesa Sand; 2010-08-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roberta Carol  Gayler et al → Black Mesa Sand, LLC; 2010-08-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Leah Renee  Johnson et al → Black Mesa Sand, LLC; 2010-08-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cheryl Christine  Taylor et al → Black Mesa Sand, LLC; 2010-08-16 to current/open; source msha-controller-operator-history