# Relationship history for MSHA mine 4503764

Current hierarchy: **Don  Sorensen → Harold Sorensen Trucking → Kalama Quarry**

- 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:** Harold  Sorensen → Kalama Quarry; 1996-02-01 to 2023-07-11; source msha-controller-operator-history
- **operator_operates_mine:** Harold Sorensen Trucking → Kalama Quarry; 2017-03-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harold  Sorensen → Harold Sorensen Trucking; 2017-03-21 to 2023-07-11; source msha-controller-operator-history
- **controller_controls_mine:** Don  Sorensen → Kalama Quarry; 2023-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Don  Sorensen → Harold Sorensen Trucking; 2023-07-12 to current/open; source msha-controller-operator-history