# Relationship history for MSHA mine 3304780

Current hierarchy: **William D Sterling; Betsy J Sterling; William M Sterling → The Beaver Excavating Co → Beaver Excavating Crushing 001**

- 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:** The Beaver Excavating Co → Beaver Excavating Crushing 001; 2022-06-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Betsy J Sterling et al → Beaver Excavating Crushing 001; 2022-06-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Betsy J Sterling et al → The Beaver Excavating Co; 2022-06-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William D Sterling et al → The Beaver Excavating Co; 2022-06-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William M Sterling et al → The Beaver Excavating Co; 2022-06-07 to current/open; source msha-controller-operator-history