# Relationship history for MSHA mine 1700777

Current hierarchy: **Michael  Cowan → Superior Crushing, Inc. → Portable Crushing Operation**

- 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:** Superior Crushing, Inc. → Portable Crushing Operation; 2005-04-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Michael  Cowan → Portable Crushing Operation; 2005-04-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Cowan → Superior Crushing, Inc.; 2005-04-21 to current/open; source msha-controller-operator-history