# Relationship history for MSHA mine 3503508

Current hierarchy: **Heidelberg Materials AG → HM Pacific Northwest, Inc. → Canby Pit**

- 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:** Pacific Rock Products LLC → Canby Pit; 2000-10-01 to 2002-09-25; source msha-controller-operator-history
- **controller_controls_mine:** Peter Kiewit Sons' Inc → Canby Pit; 2000-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Peter Kiewit Sons' Inc → Pacific Rock Products LLC; 2000-10-01 to 2002-09-25; source msha-controller-operator-history
- **operator_operates_mine:** Pacific Rock Products LLC → Canby Pit; 2002-09-26 to 2009-04-15; source msha-controller-operator-history
- **controller_controls_mine:** CSR Ltd → Canby Pit; 2002-09-26 to 2003-03-31; source msha-controller-operator-history
- **controller_controls_operator:** CSR Ltd → Pacific Rock Products LLC; 2002-09-26 to 2003-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Rinker Group Ltd → Canby Pit; 2003-04-01 to 2007-07-09; source msha-controller-operator-history
- **controller_controls_operator:** Rinker Group Ltd → Pacific Rock Products LLC; 2003-04-01 to 2007-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Cemex S A → Canby Pit; 2007-07-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cemex S A → Pacific Rock Products LLC; 2007-07-10 to 2009-04-15; source msha-controller-operator-history
- **controller_controls_mine:** Cemex S A → Canby Pit; 2008-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** CEMEX Construction Materials Pacific, LLC → Canby Pit; 2009-04-16 to 2017-06-29; source msha-controller-operator-history
- **controller_controls_operator:** Cemex S A → CEMEX Construction Materials Pacific, LLC; 2009-04-16 to 2017-06-29; source msha-controller-operator-history
- **operator_operates_mine:** HM Pacific Northwest, Inc. → Canby Pit; 2017-06-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Canby Pit; 2017-06-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → HM Pacific Northwest, Inc.; 2017-06-30 to current/open; source msha-controller-operator-history