# Relationship history for MSHA mine 3401076

Current hierarchy: **Roger E  Dahlgren → Dahlgren Contracting Inc → Milton Strip 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:** Roger E  Dahlgren → Milton Strip Mine; 1975-09-25 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dahlgren Contracting Inc → Milton Strip Mine; 1977-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roger E  Dahlgren → Dahlgren Contracting Inc; 1977-12-01 to current/open; source msha-controller-operator-history