# Relationship history for MSHA mine 0800877

Current hierarchy: **Schroeder-Manatee Ranch Inc → SMR Aggregates Inc → Quarry Drive**

- 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:** Quality Aggregates Inc → Quarry Drive; 1950-01-01 to 1998-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Wendel  Kent → Quarry Drive; 1950-01-01 to 1998-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Wendel  Kent → Quality Aggregates Inc; 1950-01-01 to 1998-06-30; source msha-controller-operator-history
- **operator_operates_mine:** SMR Aggregates Inc → Quarry Drive; 1998-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Schroeder-Manatee Ranch Inc → Quarry Drive; 1998-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Schroeder-Manatee Ranch Inc → SMR Aggregates Inc; 1998-07-01 to current/open; source msha-controller-operator-history