# Relationship history for MSHA mine 4703759

Current hierarchy: **Smart Sand Inc → Smart Sand Blair LLC → Smart Sand Blair LLC**

- 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

- **controller_controls_mine:** Hi-Crush Proppants LLC → Smart Sand Blair LLC; 2011-06-18 to 2012-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Hi-Crush Inc → Smart Sand Blair LLC; 2012-08-23 to 2024-08-04; source msha-controller-operator-history
- **operator_operates_mine:** Hi-Crush Blair LLC → Smart Sand Blair LLC; 2015-06-04 to 2022-03-03; source msha-controller-operator-history
- **controller_controls_operator:** Hi-Crush Proppants LLC → Hi-Crush Blair LLC; 2015-06-04 to 2012-08-22; source msha-controller-operator-history
- **controller_controls_operator:** Hi-Crush Inc → Hi-Crush Blair LLC; 2015-06-04 to 2022-03-03; source msha-controller-operator-history
- **operator_operates_mine:** Smart Sand Blair LLC → Smart Sand Blair LLC; 2022-03-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Smart Sand Inc → Smart Sand Blair LLC; 2022-03-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Smart Sand Inc → Smart Sand Blair LLC; 2022-03-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** HC Minerals Inc → Smart Sand Blair LLC; 2024-08-05 to 2025-08-10; source msha-controller-operator-history
- **controller_controls_operator:** HC Minerals Inc → Hi-Crush Blair LLC; 2024-08-05 to 2022-03-03; source msha-controller-operator-history
- **controller_controls_mine:** Iron Oak Energy Solutions LLC → Smart Sand Blair LLC; 2025-08-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Iron Oak Energy Solutions LLC → Hi-Crush Blair LLC; 2025-08-11 to 2022-03-03; source msha-controller-operator-history