# Relationship history for MSHA mine 0301940

Current hierarchy: **Chad Rubert  Smith → Elizabeth Quarry Inc → Elizabeth Quarry Inc**

- 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:** Rocky Ridge Quarry, Inc. → Elizabeth Quarry Inc; 2006-10-11 to 2015-02-01; source msha-controller-operator-history
- **controller_controls_mine:** Delmer  Sanders → Elizabeth Quarry Inc; 2006-10-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Delmer  Sanders → Rocky Ridge Quarry, Inc.; 2006-10-11 to 2015-02-01; source msha-controller-operator-history
- **operator_operates_mine:** Elizabeth Quarry Inc → Elizabeth Quarry Inc; 2015-02-02 to 2018-11-20; source msha-controller-operator-history
- **controller_controls_mine:** John R  Walker → Elizabeth Quarry Inc; 2015-02-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John R  Walker → Elizabeth Quarry Inc; 2015-02-02 to 2018-11-20; source msha-controller-operator-history
- **operator_operates_mine:** Elizabeth Quarry Inc → Elizabeth Quarry Inc; 2018-11-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Chad Rubert  Smith → Elizabeth Quarry Inc; 2018-11-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chad Rubert  Smith → Elizabeth Quarry Inc; 2018-11-21 to current/open; source msha-controller-operator-history