# Relationship history for MSHA mine 4503639

Current hierarchy: **Elton L Mason → Washington State Trucking → Washington State Trucking**

- 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:** Elma Rock N Redi-Mix → Washington State Trucking; 2007-10-22 to 2016-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Steve  Randle  et al → Washington State Trucking; 2007-10-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steve  Randle  et al → Elma Rock N Redi-Mix; 2007-10-22 to 2016-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Randolph  Barrett  et al → Elma Rock N Redi-Mix; 2007-10-22 to 2016-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Washington State Trucking → Washington State Trucking; 2017-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Elton L Mason → Washington State Trucking; 2017-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Elton L Mason → Washington State Trucking; 2017-01-01 to current/open; source msha-controller-operator-history