# Relationship history for MSHA mine 0405497

Current hierarchy: **Atna Resources Ltd. → C.R. Briggs → CR Briggs Underground**

- 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:** Canyon Resources Corp → CR Briggs Underground; 1990-08-27 to 2008-03-17; source msha-controller-operator-history
- **operator_operates_mine:** C.R. Briggs → CR Briggs Underground; 2002-02-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Canyon Resources Corp → C.R. Briggs; 2002-02-26 to 2008-03-17; source msha-controller-operator-history
- **controller_controls_mine:** Atna Resources Ltd. → CR Briggs Underground; 2008-03-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Atna Resources Ltd. → C.R. Briggs; 2008-03-18 to current/open; source msha-controller-operator-history