# Relationship history for MSHA mine 4406622

Current hierarchy: **Smith Glen A → Glen Allen Mining Inc → No 1 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

- **controller_controls_mine:** United  Company → No 1 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Wellmore Coal Corp → No 1 Mine; 1990-12-01 to 1991-10-20; source msha-controller-operator-history
- **controller_controls_operator:** United  Company → Wellmore Coal Corp; 1990-12-01 to 1991-10-20; source msha-controller-operator-history
- **operator_operates_mine:** Glen Allen Mining Inc → No 1 Mine; 1991-10-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Smith Glen A → No 1 Mine; 1991-10-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Smith Glen A → Glen Allen Mining Inc; 1991-10-21 to current/open; source msha-controller-operator-history