# Relationship history for MSHA mine 2100200

Current hierarchy: **Eveleth Mines Llc → Evtac Mining → EVTAC MINE**

- 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:** Eveleth Mines → EVTAC MINE; 1950-01-01 to 1987-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Eveleth Taconite Co & Eveleth Expansion Co → EVTAC MINE; 1950-01-01 to 1987-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Eveleth Taconite Co & Eveleth Expansion Co → Eveleth Mines; 1950-01-01 to 1987-01-31; source msha-controller-operator-history
- **operator_operates_mine:** Oglebay Norton Taconite Company → EVTAC MINE; 1987-02-01 to 1996-12-03; source msha-controller-operator-history
- **controller_controls_mine:** Oglebay Norton Company → EVTAC MINE; 1987-02-01 to 1996-12-03; source msha-controller-operator-history
- **controller_controls_operator:** Oglebay Norton Company → Oglebay Norton Taconite Company; 1987-02-01 to 1996-12-03; source msha-controller-operator-history
- **operator_operates_mine:** Evtac Mining → EVTAC MINE; 1996-12-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Eveleth Mines Llc → EVTAC MINE; 1996-12-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eveleth Mines Llc → Evtac Mining; 1996-12-04 to current/open; source msha-controller-operator-history