# Relationship history for MSHA mine 5001687

Current hierarchy: **ASRC Primus; Atco Frontec Corp → Arctec Alaska JV → ARCTEC Alaska Portable # 1**

- 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:** Arctec Alaska JV → ARCTEC Alaska Portable # 1; 2001-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Atco Frontec Corp  et al → ARCTEC Alaska Portable # 1; 2001-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Atco Frontec Corp  et al → Arctec Alaska JV; 2001-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** ASRC Primus et al → Arctec Alaska JV; 2001-04-01 to current/open; source msha-controller-operator-history