# Relationship history for MSHA mine 4606752

Current hierarchy: **Lawson W  Hamilton Jr → Hansford Coal Company → No 3 Surface**

- 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:** Lawson W  Hamilton Jr → No 3 Surface; 1974-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hansford Coal Company → No 3 Surface; 1984-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lawson W  Hamilton Jr → Hansford Coal Company; 1984-03-01 to current/open; source msha-controller-operator-history