# Relationship history for MSHA mine 0201990

Current hierarchy: **Nicoll Construction Company → Nicoll Construction Company → Cedar Rapids-Seattle Itt**

- 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:** Nicoll Construction Company → Cedar Rapids-Seattle Itt; 1980-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Nicoll Construction Company → Cedar Rapids-Seattle Itt; 1980-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Nicoll Construction Company → Nicoll Construction Company; 1980-06-01 to current/open; source msha-controller-operator-history