# Relationship history for MSHA mine 2601776

Current hierarchy: **Hau Sun  Ho → Geo-Nevada Inc. → Spring Valley**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Nova Technology International Inc → Spring Valley; 1981-11-01 to 1988-03-30; source msha-controller-operator-history
- **controller_controls_mine:** Nova Technology International Inc → Spring Valley; 1981-11-01 to 1988-03-30; source msha-controller-operator-history
- **controller_controls_operator:** Nova Technology International Inc → Nova Technology International Inc; 1981-11-01 to 1988-03-30; source msha-controller-operator-history
- **operator_operates_mine:** Gold Bug Joint Venture → Spring Valley; 1988-03-31 to 2002-01-03; source msha-controller-operator-history
- **controller_controls_mine:** Cahan Leslie L & Robert W Craig → Spring Valley; 1988-03-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cahan Leslie L & Robert W Craig → Gold Bug Joint Venture; 1988-03-31 to 2002-01-03; source msha-controller-operator-history
- **operator_operates_mine:** Geo-Nevada Inc. → Spring Valley; 2002-01-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hau Sun  Ho → Spring Valley; 2002-01-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hau Sun  Ho → Geo-Nevada Inc.; 2002-01-04 to current/open; source msha-controller-operator-history