# Relationship history for MSHA mine 4501227

Current hierarchy: **Heidelberg Materials AG → HM Pacific Northwest, Inc. → Cadman Black Diamond**

- 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:** Flintstone Sand & Gravel Inc → Cadman Black Diamond; 1950-01-01 to 1989-01-03; source msha-controller-operator-history
- **controller_controls_mine:** Richard  Todnem → Cadman Black Diamond; 1950-01-01 to 1989-01-03; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Todnem → Flintstone Sand & Gravel Inc; 1950-01-01 to 1989-01-03; source msha-controller-operator-history
- **operator_operates_mine:** Cadman Sand & Gravel Inc → Cadman Black Diamond; 1989-01-04 to 1991-01-01; source msha-controller-operator-history
- **controller_controls_mine:** Paul J  Taylor  et al → Cadman Black Diamond; 1989-01-04 to 1991-01-01; source msha-controller-operator-history
- **controller_controls_operator:** Paul J  Taylor  et al → Cadman Sand & Gravel Inc; 1989-01-04 to 1991-01-01; source msha-controller-operator-history
- **operator_operates_mine:** Cadman (Black Diamond) Inc → Cadman Black Diamond; 1991-01-02 to 2023-01-30; source msha-controller-operator-history
- **controller_controls_mine:** Cimenteries Cbr Cementbedrijven → Cadman Black Diamond; 1991-01-02 to 2000-07-20; source msha-controller-operator-history
- **controller_controls_operator:** Cimenteries Cbr Cementbedrijven → Cadman (Black Diamond) Inc; 1991-01-02 to 2000-07-20; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Cadman Black Diamond; 2000-07-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Cadman (Black Diamond) Inc; 2000-07-21 to 2023-01-30; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Cadman Black Diamond; 2017-06-30 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** HM Pacific Northwest, Inc. → Cadman Black Diamond; 2023-01-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → HM Pacific Northwest, Inc.; 2023-01-31 to current/open; source msha-controller-operator-history