# Relationship history for MSHA mine 3609970

Current hierarchy: **Rodney S  Brace → Brace Stone → Power Stone Cobb Quarry**

- 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

- **controller_controls_mine:** Joe E  Calamari → Power Stone Cobb Quarry; 2008-06-26 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Joe Squid Inc. → Power Stone Cobb Quarry; 2011-11-10 to 2012-11-27; source msha-controller-operator-history
- **controller_controls_operator:** Joe E  Calamari → Joe Squid Inc.; 2011-11-10 to 2012-11-27; source msha-controller-operator-history
- **operator_operates_mine:** Brace Stone → Power Stone Cobb Quarry; 2012-11-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Rodney S  Brace → Power Stone Cobb Quarry; 2012-11-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rodney S  Brace → Brace Stone; 2012-11-28 to current/open; source msha-controller-operator-history