# Relationship history for MSHA mine 2301929

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials, Inc. → Plant # 1**

- 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

- **controller_controls_mine:** Ashland Inc → Plant # 1; 1950-01-01 to 2006-08-27; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Plant # 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Everett Holding Co  et al → Plant # 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Everett Quarries Company Inc → Plant # 1; 1985-07-01 to 2011-07-17; source msha-controller-operator-history
- **controller_controls_operator:** Everett Holding Co  et al → Everett Quarries Company Inc; 1985-07-01 to 2011-07-17; source msha-controller-operator-history
- **controller_controls_operator:** Clarkson Construction Co et al → Everett Quarries Company Inc; 1985-07-01 to 2011-07-17; source msha-controller-operator-history
- **controller_controls_mine:** Con-Agg Llc → Plant # 1; 2001-12-28 to 2010-09-14; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Plant # 1; 2006-08-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Summit Materials LLC → Plant # 1; 2010-09-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** APAC- Kansas, Inc. → Plant # 1; 2011-07-18 to 2016-05-19; source msha-controller-operator-history
- **controller_controls_operator:** Ashland Inc → APAC- Kansas, Inc.; 2011-07-18 to 2006-08-27; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → APAC- Kansas, Inc.; 2011-07-18 to 2016-05-19; source msha-controller-operator-history
- **operator_operates_mine:** Con-Agg Companies, LLC → Plant # 1; 2016-05-20 to 2026-03-23; source msha-controller-operator-history
- **controller_controls_operator:** Con-Agg Llc → Con-Agg Companies, LLC; 2016-05-20 to 2010-09-14; source msha-controller-operator-history
- **controller_controls_operator:** Summit Materials LLC → Con-Agg Companies, LLC; 2016-05-20 to 2026-03-23; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc. → Plant # 1; 2026-03-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc.; 2026-03-24 to current/open; source msha-controller-operator-history