# Relationship history for MSHA mine 0201760

Current hierarchy: **Hunt Robert A → Con-American Mining Company Inc → Dry Hills Mine**

- 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:** William V Butler → Dry Hills Mine; 1979-11-01 to 1981-02-23; source msha-controller-operator-history
- **controller_controls_mine:** Butler William V → Dry Hills Mine; 1979-11-01 to 1981-02-23; source msha-controller-operator-history
- **controller_controls_operator:** Butler William V → William V Butler; 1979-11-01 to 1981-02-23; source msha-controller-operator-history
- **operator_operates_mine:** Con-American Mining Company Inc → Dry Hills Mine; 1981-02-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hunt Robert A → Dry Hills Mine; 1981-02-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hunt Robert A → Con-American Mining Company Inc; 1981-02-24 to current/open; source msha-controller-operator-history