# Relationship history for MSHA mine 5001947

Current hierarchy: **Cap  Shafer; Cam  Shafer; Brok  Shafer → Alaska Marine Excavation LLC. → Portable #1 Crusher**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Alaska Marine Excavation LLC. → Portable #1 Crusher; 2011-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cam  Shafer et al → Portable #1 Crusher; 2011-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cam  Shafer et al → Alaska Marine Excavation LLC.; 2011-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brok  Shafer et al → Alaska Marine Excavation LLC.; 2011-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cap  Shafer et al → Alaska Marine Excavation LLC.; 2011-01-01 to current/open; source msha-controller-operator-history