# Relationship history for MSHA mine 1103293

Current hierarchy: **Dave  Hamman; Karen  Heil → H & H Stone LLC → Sand Storm 620**

- 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:** H & H Stone LLC → Sand Storm 620; 2019-03-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Karen  Heil et al → Sand Storm 620; 2019-03-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Karen  Heil et al → H & H Stone LLC; 2019-03-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dave  Hamman et al → H & H Stone LLC; 2019-03-20 to current/open; source msha-controller-operator-history