# Relationship history for MSHA mine 5001938

Current hierarchy: **Greg  Clayton → GMC Contracting, Inc → Portable Crusher #1**

- 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:** GMC Contracting, Inc → Portable Crusher #1; 2010-06-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Greg  Clayton et al → Portable Crusher #1; 2010-06-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Greg  Clayton et al → GMC Contracting, Inc; 2010-06-10 to current/open; source msha-controller-operator-history