# Relationship history for MSHA mine 1401702

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials, Inc. → Silver Lake West Sand**

- 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:** Martin Marietta Materials Inc → Silver Lake West Sand; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Builders Choice Aggregates → Silver Lake West Sand; 2009-04-27 to 2026-03-22; source msha-controller-operator-history
- **controller_controls_mine:** Joseph D  Marney  et al → Silver Lake West Sand; 2009-04-27 to 2014-10-02; source msha-controller-operator-history
- **controller_controls_operator:** Joseph D  Marney  et al → Builders Choice Aggregates; 2009-04-27 to 2014-10-02; source msha-controller-operator-history
- **controller_controls_operator:** Larry D  Marney  et al → Builders Choice Aggregates; 2009-04-27 to 2014-10-02; source msha-controller-operator-history
- **controller_controls_mine:** Summit Materials LLC → Silver Lake West Sand; 2014-10-03 to 2022-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Summit Materials LLC → Builders Choice Aggregates; 2014-10-03 to 2022-03-31; source msha-controller-operator-history
- **controller_controls_mine:** N R Hamm et al → Silver Lake West Sand; 2022-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** N R Hamm et al → Builders Choice Aggregates; 2022-04-01 to 2026-03-22; source msha-controller-operator-history
- **controller_controls_operator:** Summit Materials LLC et al → Builders Choice Aggregates; 2022-04-01 to 2026-03-22; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc. → Silver Lake West Sand; 2026-03-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc.; 2026-03-23 to current/open; source msha-controller-operator-history