# Relationship history for MSHA mine 2900418

Current hierarchy: **Vulcan Materials Company → CalMat Co → Shakespeare 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:** Albuquerque Gravel Products Company → Shakespeare Pit; 1950-01-01 to 1989-02-12; source msha-controller-operator-history
- **controller_controls_mine:** Sundt Corp → Shakespeare Pit; 1950-01-01 to 1989-02-12; source msha-controller-operator-history
- **controller_controls_operator:** Sundt Corp → Albuquerque Gravel Products Company; 1950-01-01 to 1989-02-12; source msha-controller-operator-history
- **operator_operates_mine:** Calmat Company Of New Mexico → Shakespeare Pit; 1989-02-13 to 1999-01-05; source msha-controller-operator-history
- **controller_controls_mine:** Calmat Company → Shakespeare Pit; 1989-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Calmat Company → Calmat Company Of New Mexico; 1989-02-13 to 1999-01-05; source msha-controller-operator-history
- **operator_operates_mine:** Calmat Co of New Mexico → Shakespeare Pit; 1999-01-06 to 2004-01-06; source msha-controller-operator-history
- **controller_controls_mine:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → Shakespeare Pit; 1999-01-06 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → Calmat Co of New Mexico; 1999-01-06 to 2004-01-06; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Shakespeare Pit; 2002-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** CalMat Co → Shakespeare Pit; 2004-01-07 to 2011-10-02; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → CalMat Co; 2004-01-07 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Vulcan Materials Company → Shakespeare Pit; 2007-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → Calmat Co of New Mexico; 2007-11-16 to 2004-01-06; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → CalMat Co; 2007-11-16 to 2011-10-02; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge Southwest Inc → Shakespeare Pit; 2011-10-03 to 2014-08-28; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge Southwest Inc; 2011-10-03 to 2014-08-28; source msha-controller-operator-history
- **operator_operates_mine:** CalMat Co → Shakespeare Pit; 2014-08-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → CalMat Co; 2014-08-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → CalMat Co; 2014-08-29 to 2007-11-15; source msha-controller-operator-history