# Relationship history for MSHA mine 1900304

Current hierarchy: **Egerton Inc → Emaral Corp → Grafton Plant**

- 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:** E L Dauphinais Inc → Grafton Plant; 1950-01-01 to 1988-09-15; source msha-controller-operator-history
- **controller_controls_mine:** Dauphinais Albert A Et Al → Grafton Plant; 1950-01-01 to 1988-09-15; source msha-controller-operator-history
- **controller_controls_operator:** Dauphinais Albert A Et Al → E L Dauphinais Inc; 1950-01-01 to 1988-09-15; source msha-controller-operator-history
- **controller_controls_mine:** Egerton Inc → Grafton Plant; 1988-09-13 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Emaral Corp → Grafton Plant; 1988-09-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Egerton Inc → Emaral Corp; 1988-09-16 to current/open; source msha-controller-operator-history