# Relationship history for MSHA mine 2000767

Current hierarchy: **Amrize Ltd → Meyer Material CO, LLC → Chelsea Plant**

- 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:** Meyer Material Acquisition Corp Et Al → Chelsea Plant; 1950-01-01 to 2011-07-11; source msha-controller-operator-history
- **operator_operates_mine:** Klumpp Brothers Gravel Company → Chelsea Plant; 1950-01-01 to 1985-04-29; source msha-controller-operator-history
- **controller_controls_mine:** William  Sturgill → Chelsea Plant; 1950-01-01 to 1985-04-29; source msha-controller-operator-history
- **controller_controls_operator:** William  Sturgill → Klumpp Brothers Gravel Company; 1950-01-01 to 1985-04-29; source msha-controller-operator-history
- **operator_operates_mine:** Chelsea Aggregate Corp → Chelsea Plant; 1985-04-30 to 1999-01-25; source msha-controller-operator-history
- **controller_controls_mine:** David  Pachota → Chelsea Plant; 1985-04-30 to 1999-01-25; source msha-controller-operator-history
- **controller_controls_operator:** David  Pachota → Chelsea Aggregate Corp; 1985-04-30 to 1999-01-25; source msha-controller-operator-history
- **operator_operates_mine:** Bill Smith Sand & Gravel → Chelsea Plant; 1999-01-26 to 2011-07-11; source msha-controller-operator-history
- **controller_controls_mine:** Aggregate Industries PLC → Chelsea Plant; 2004-06-10 to 2009-04-29; source msha-controller-operator-history
- **controller_controls_operator:** Aggregate Industries PLC → Bill Smith Sand & Gravel; 2004-06-10 to 2009-04-29; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → Chelsea Plant; 2009-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Bill Smith Sand & Gravel; 2009-04-30 to 2011-07-11; source msha-controller-operator-history
- **operator_operates_mine:** Meyer Material CO, LLC → Chelsea Plant; 2011-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Meyer Material Acquisition Corp Et Al → Meyer Material CO, LLC; 2011-07-12 to 2011-07-11; source msha-controller-operator-history
- **controller_controls_mine:** Aggregate Industries PLC → Chelsea Plant; 2011-07-12 to 2015-07-09; source msha-controller-operator-history
- **controller_controls_operator:** Aggregate Industries PLC → Meyer Material CO, LLC; 2011-07-12 to 2015-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → Chelsea Plant; 2015-07-10 to 2025-06-22; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Meyer Material CO, LLC; 2015-07-10 to 2025-06-22; source msha-controller-operator-history
- **controller_controls_mine:** Amrize Ltd → Chelsea Plant; 2025-06-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Amrize Ltd → Meyer Material CO, LLC; 2025-06-23 to current/open; source msha-controller-operator-history