# Relationship history for MSHA mine 2600785

Current hierarchy: **Teck Resources Limited → Cominco American Resources Inc → BUCKHORN 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Bar Resources Inc → BUCKHORN MINE; 1950-01-01 to 1980-05-12; source msha-controller-operator-history
- **controller_controls_mine:** Bar Resources Ltd → BUCKHORN MINE; 1950-01-01 to 1980-05-12; source msha-controller-operator-history
- **controller_controls_operator:** Bar Resources Ltd → Bar Resources Inc; 1950-01-01 to 1980-05-12; source msha-controller-operator-history
- **operator_operates_mine:** Bethex Corp → BUCKHORN MINE; 1980-05-13 to 1983-09-27; source msha-controller-operator-history
- **controller_controls_mine:** Bethlehem Copper Corp → BUCKHORN MINE; 1980-05-13 to 1983-09-27; source msha-controller-operator-history
- **controller_controls_operator:** Bethlehem Copper Corp → Bethex Corp; 1980-05-13 to 1983-09-27; source msha-controller-operator-history
- **operator_operates_mine:** Cominco American Resources Inc → BUCKHORN MINE; 1983-09-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Teck Resources Limited → BUCKHORN MINE; 1983-09-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Teck Resources Limited → Cominco American Resources Inc; 1983-09-28 to current/open; source msha-controller-operator-history