# Relationship history for MSHA mine 4605855

Current hierarchy: **Groves S J & Sons Company → Gopher Mining Company → Sims Mt 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:** Groves S J & Sons Company → Sims Mt Surface; 1974-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Gopher Mining Company → Sims Mt Surface; 1978-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Groves S J & Sons Company → Gopher Mining Company; 1978-08-01 to current/open; source msha-controller-operator-history