# Relationship history for MSHA mine 3401758

Current hierarchy: **Cornell L T & John → Cornell Construction Company Inc → Walker #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

- **controller_controls_mine:** Cornell L T & John → Walker #1; 1980-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cornell Construction Company Inc → Walker #1; 1991-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cornell L T & John → Cornell Construction Company Inc; 1991-06-01 to current/open; source msha-controller-operator-history