# Relationship history for MSHA mine 4104704

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials Southwest, Inc → 211**

- 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:** Zachary  Tausch  et al → 211; 2006-08-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → 211; 2007-11-26 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Custom Crushed Stone Inc → 211; 2007-12-18 to 2011-06-17; source msha-controller-operator-history
- **controller_controls_operator:** Zachary  Tausch  et al → Custom Crushed Stone Inc; 2007-12-18 to 2011-06-17; source msha-controller-operator-history
- **controller_controls_operator:** Vernon  Tausch  et al → Custom Crushed Stone Inc; 2007-12-18 to 2011-06-17; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials Southwest, Inc → 211; 2011-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials Southwest, Inc; 2011-06-18 to current/open; source msha-controller-operator-history