# Relationship history for MSHA mine 1901184

Current hierarchy: **Norman  Dellaghelfa Jr → N Della Inc → Della - Screen**

- 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:** N Della Inc → Della - Screen; 2008-10-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Roberta M  Dellaghelfa → Della - Screen; 2008-10-28 to 2013-09-02; source msha-controller-operator-history
- **controller_controls_operator:** Roberta M  Dellaghelfa → N Della Inc; 2008-10-28 to 2013-09-02; source msha-controller-operator-history
- **controller_controls_mine:** Norman  Dellaghelfa Jr → Della - Screen; 2013-09-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Norman  Dellaghelfa Jr → N Della Inc; 2013-09-03 to current/open; source msha-controller-operator-history