# Relationship history for MSHA mine 2103337

Current hierarchy: **Michael D Luukkonen → NTT of Minnesota, Inc. → CEC-2**

- 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:** Michael D Luukkonen → CEC-2; 1992-08-18 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** NTT of Minnesota, Inc. → CEC-2; 2002-10-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael D Luukkonen → NTT of Minnesota, Inc.; 2002-10-30 to current/open; source msha-controller-operator-history