# Relationship history for MSHA mine 4202413

Current hierarchy: **Allyson P.  Muir; Curtis R.  Muir → CMC Sand & Gravel → CMC Sand & Gravel Portable**

- 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:** CMC Sand & Gravel → CMC Sand & Gravel Portable; 2005-06-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Curtis R.  Muir et al → CMC Sand & Gravel Portable; 2005-06-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Curtis R.  Muir et al → CMC Sand & Gravel; 2005-06-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Allyson P.  Muir et al → CMC Sand & Gravel; 2005-06-14 to current/open; source msha-controller-operator-history