# Relationship history for MSHA mine 2002516

Current hierarchy: **Holcim Ltd → Dundee Cement Company → Dundee Mine Or Dundee Cement Co (Quarry)**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Holcim Ltd → Dundee Mine Or Dundee Cement Co (Quarry); 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dundee Cement Company → Dundee Mine Or Dundee Cement Co (Quarry); 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Dundee Cement Company; 1979-01-01 to current/open; source msha-controller-operator-history