# Relationship history for MSHA mine 2602131

Current hierarchy: **Welsh J D & Associates Inc → Zephyr Resources Inc → Summit Project**

- 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:** Welsh J D & Associates Inc → Summit Project; 1989-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Zephyr Resources Inc → Summit Project; 1989-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Welsh J D & Associates Inc → Zephyr Resources Inc; 1989-09-01 to current/open; source msha-controller-operator-history