# Relationship history for MSHA mine 4503750

Current hierarchy: **Michael T  Crawford; Jerome W  Fisher → Skagit Aggregates LLC → Hamilton**

- 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

- **controller_controls_mine:** Michael T  Crawford et al → Hamilton; 2012-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Taiheiyo Cement Corp → Hamilton; 2015-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** CPC Materials Inc. → Hamilton; 2016-08-19 to 2025-06-15; source msha-controller-operator-history
- **controller_controls_operator:** Taiheiyo Cement Corp → CPC Materials Inc.; 2016-08-19 to 2025-06-15; source msha-controller-operator-history
- **operator_operates_mine:** Skagit Aggregates LLC → Hamilton; 2025-06-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael T  Crawford et al → Skagit Aggregates LLC; 2025-06-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jerome W  Fisher et al → Skagit Aggregates LLC; 2025-06-16 to current/open; source msha-controller-operator-history