# Relationship history for MSHA mine 2102971

Current hierarchy: **Michael C  Brandt → Morris Sand & Gravel,Inc. → Crusher #2 Cedar Rapids**

- 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:** Henry B  Thieman → Crusher #2 Cedar Rapids; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** West Central Gravel Inc. → Crusher #2 Cedar Rapids; 1987-09-01 to 2014-01-15; source msha-controller-operator-history
- **controller_controls_operator:** Henry B  Thieman → West Central Gravel Inc.; 1987-09-01 to 2014-01-15; source msha-controller-operator-history
- **controller_controls_mine:** Michael C  Brandt → Crusher #2 Cedar Rapids; 1992-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Morris Sand & Gravel,Inc. → Crusher #2 Cedar Rapids; 2014-01-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael C  Brandt → Morris Sand & Gravel,Inc.; 2014-01-16 to current/open; source msha-controller-operator-history