# Relationship history for MSHA mine 4605022

Current hierarchy: **Robert L  Worley → Underground Energy Corp → No 2 Deep**

- 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:** Robert L  Worley → No 2 Deep; 1975-06-14 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Underground Energy Corp → No 2 Deep; 1976-01-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert L  Worley → Underground Energy Corp; 1976-01-21 to current/open; source msha-controller-operator-history