# Relationship history for MSHA mine 4105388

Current hierarchy: **Black Mountain Sand Holdings LLC; Natural Gas Partners → Black Mountain Sand Permian, LLC. → Sealy Smith**

- 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 Mountain Sand Permian, LLC. → Sealy Smith; 2018-09-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Natural Gas Partners et al → Sealy Smith; 2018-09-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Natural Gas Partners et al → Black Mountain Sand Permian, LLC.; 2018-09-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Black Mountain Sand Holdings LLC et al → Black Mountain Sand Permian, LLC.; 2018-09-21 to current/open; source msha-controller-operator-history