# Relationship history for MSHA mine 1519881

Current hierarchy: **Gulin A  Ertugrul → A&M Engineering and Environmental Services, Inc. → Wallace 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:** A&M Engineering and Environmental Services, Inc. → Wallace Mine; 2019-11-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gulin A  Ertugrul → Wallace Mine; 2019-11-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gulin A  Ertugrul → A&M Engineering and Environmental Services, Inc.; 2019-11-15 to current/open; source msha-controller-operator-history