# Relationship history for MSHA mine 0504769

Current hierarchy: **James C  Marvel Jr → Ready Mixed Concrete Company → Del Camino Sand & Gravel Mine**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Frank P Spratlen et al → Del Camino Sand & Gravel Mine; 1978-07-01 to 2004-09-12; source msha-controller-operator-history
- **operator_operates_mine:** Owens Brothers Concrete Co. → Del Camino Sand & Gravel Mine; 2002-12-11 to 2004-09-27; source msha-controller-operator-history
- **controller_controls_mine:** Mike E Owens → Del Camino Sand & Gravel Mine; 2002-12-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mike E Owens → Owens Brothers Concrete Co.; 2002-12-11 to 2004-09-27; source msha-controller-operator-history
- **controller_controls_mine:** Boral Limited → Del Camino Sand & Gravel Mine; 2004-09-13 to 2018-07-01; source msha-controller-operator-history
- **operator_operates_mine:** Ready Mixed Concrete Company → Del Camino Sand & Gravel Mine; 2004-09-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Boral Limited → Ready Mixed Concrete Company; 2004-09-28 to 2018-07-01; source msha-controller-operator-history
- **controller_controls_operator:** Frank P Spratlen et al → Ready Mixed Concrete Company; 2004-09-28 to 2004-09-12; source msha-controller-operator-history
- **controller_controls_mine:** James C  Marvel Jr → Del Camino Sand & Gravel Mine; 2018-07-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James C  Marvel Jr → Ready Mixed Concrete Company; 2018-07-02 to current/open; source msha-controller-operator-history