# Relationship history for MSHA mine 5001508

Current hierarchy: **Kvaerner A S → Kvaerner Environmental → Aj 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:** Wgm Inc → Aj Mine; 1986-07-01 to 1988-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Watts-Griffis & Mc Quat Ltd → Aj Mine; 1986-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Watts-Griffis & Mc Quat Ltd → Wgm Inc; 1986-07-01 to 1988-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Echo Bay Mines Ltd → Aj Mine; 1987-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Echo Bay Alaska Inc → Aj Mine; 1988-06-01 to 1997-08-07; source msha-controller-operator-history
- **controller_controls_operator:** Echo Bay Mines Ltd → Echo Bay Alaska Inc; 1988-06-01 to 1997-08-07; source msha-controller-operator-history
- **operator_operates_mine:** Kvaerner Environmental → Aj Mine; 1997-08-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kvaerner A S → Aj Mine; 1997-08-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kvaerner A S → Kvaerner Environmental; 1997-08-08 to current/open; source msha-controller-operator-history