# Relationship history for MSHA mine 1519090

Current hierarchy: **Thomas R  Hamilton → Nally & Hamilton Enterprises, Inc. → Betsy Branch**

- 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:** Thomas R  Hamilton et al → Betsy Branch; 1974-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Nally & Hamilton Enterprises, Inc. → Betsy Branch; 2007-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas R  Hamilton et al → Nally & Hamilton Enterprises, Inc.; 2007-03-01 to current/open; source msha-controller-operator-history