# Relationship history for MSHA mine 3303618

Current hierarchy: **Grimes Corwin → Minerva Mining Inc → Grimes 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

- **operator_operates_mine:** Minerva Mining Inc → Grimes Strip; 1977-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Grimes Corwin → Grimes Strip; 1977-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Grimes Corwin → Minerva Mining Inc; 1977-04-01 to current/open; source msha-controller-operator-history