# Relationship history for MSHA mine 0501580

Current hierarchy: **Sigismond Richard A → Aquarius Mining Company → Comstock**

- 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:** Aquarius Mining Company → Comstock; 1983-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sigismond Richard A → Comstock; 1983-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sigismond Richard A → Aquarius Mining Company; 1983-04-01 to current/open; source msha-controller-operator-history