# Relationship history for MSHA mine 5001639

Current hierarchy: **Northwest Carbonates; Bleeck Management → Columbia River Carbonates → Calder**

- 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:** Northwest Carbonates  et al → Calder; 1986-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Veco Inc → Calder; 1987-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Prince Of Wales Mining Llc → Calder; 1997-06-01 to 1998-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Sealaska Corp → Calder; 1997-06-01 to 1998-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Sealaska Corp → Prince Of Wales Mining Llc; 1997-06-01 to 1998-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Eastwind-Div/Norcon Inc → Calder; 1998-05-01 to 2000-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Veco Inc → Eastwind-Div/Norcon Inc; 1998-05-01 to 2000-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Sea Cal Llc → Calder; 2000-06-01 to 2012-01-24; source msha-controller-operator-history
- **controller_controls_mine:** Sealaska Corp → Calder; 2000-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sealaska Corp → Sea Cal Llc; 2000-06-01 to 2012-01-24; source msha-controller-operator-history
- **operator_operates_mine:** Columbia River Carbonates → Calder; 2012-01-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Northwest Carbonates  et al → Columbia River Carbonates; 2012-01-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bleeck Management  et al → Columbia River Carbonates; 2012-01-25 to current/open; source msha-controller-operator-history