# Relationship history for MSHA mine 3607309

Current hierarchy: **Grigas Charles & Joseph Butera → Grigas & Butera Coal Comapany → Grigas And Butera Strip**

- 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

- **controller_controls_mine:** Grigas Charles & Joseph Butera → Grigas And Butera Strip; 1977-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Grigas & Butera Coal Comapany → Grigas And Butera Strip; 1982-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Grigas Charles & Joseph Butera → Grigas & Butera Coal Comapany; 1982-05-01 to current/open; source msha-controller-operator-history