# Relationship history for MSHA mine 2600639

Current hierarchy: **Roscorp Inc; American Borate Corp → American Borate Company → Lathrop 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** American Borate Company → Lathrop Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** American Borate Corp  et al → Lathrop Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** American Borate Corp  et al → American Borate Company; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roscorp Inc  et al → American Borate Company; 1950-01-01 to current/open; source msha-controller-operator-history