# Relationship history for MSHA mine 1518724

Current hierarchy: **Michael G  Webb → Marissa Mining Company Inc. → #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:** Marissa Mining Company Inc. → #1; 2004-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Michael G  Webb → #1; 2004-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael G  Webb → Marissa Mining Company Inc.; 2004-02-27 to current/open; source msha-controller-operator-history