# Relationship history for MSHA mine 0502254

Current hierarchy: **Coors William K → Alma American Milling Corp → American Mill**

- 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:** C M Inc → American Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ams Inc Of Nevada → American Mill; 1981-04-01 to 1982-02-16; source msha-controller-operator-history
- **controller_controls_operator:** C M Inc → Ams Inc Of Nevada; 1981-04-01 to 1982-02-16; source msha-controller-operator-history
- **operator_operates_mine:** Alma American Milling Corp → American Mill; 1982-02-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Coors William K → American Mill; 1982-02-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Coors William K → Alma American Milling Corp; 1982-02-17 to current/open; source msha-controller-operator-history