# Relationship history for MSHA mine 2401601

Current hierarchy: **Johnsrud Ralph A & Ronald Toomer → R & R Prospectors Inc → Big Chance Placer**

- 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:** R & R Prospectors Inc → Big Chance Placer; 1981-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Johnsrud Ralph A & Ronald Toomer → Big Chance Placer; 1981-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnsrud Ralph A & Ronald Toomer → R & R Prospectors Inc; 1981-01-01 to current/open; source msha-controller-operator-history