# Relationship history for MSHA mine 0403206

Current hierarchy: **Shasta Mine Associates-Bird Drilling → Shasta Bird Mine Associates → Brown Bear Mine**

- 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:** Brown Bear Mining Company → Brown Bear Mine; 1950-01-01 to 1980-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Cochrane F M-Trustee Et Al → Brown Bear Mine; 1950-01-01 to 1980-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Cochrane F M-Trustee Et Al → Brown Bear Mining Company; 1950-01-01 to 1980-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Shasta Bird Mine Associates → Brown Bear Mine; 1980-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Shasta Mine Associates-Bird Drilling → Brown Bear Mine; 1980-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shasta Mine Associates-Bird Drilling → Shasta Bird Mine Associates; 1980-09-01 to current/open; source msha-controller-operator-history