# Relationship history for MSHA mine 0404591

Current hierarchy: **Mickelson Joy → Twin Sisters Mine → Twin Sisters**

- 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:** Windigo Mining Company → Twin Sisters; 1982-05-01 to 1991-04-23; source msha-controller-operator-history
- **controller_controls_mine:** Hall Paul-Glen Emery Et Al → Twin Sisters; 1982-05-01 to 1991-04-23; source msha-controller-operator-history
- **controller_controls_operator:** Hall Paul-Glen Emery Et Al → Windigo Mining Company; 1982-05-01 to 1991-04-23; source msha-controller-operator-history
- **operator_operates_mine:** Twin Sisters Mine → Twin Sisters; 1991-04-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mickelson Joy → Twin Sisters; 1991-04-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mickelson Joy → Twin Sisters Mine; 1991-04-24 to current/open; source msha-controller-operator-history