# Relationship history for MSHA mine 0405805

Current hierarchy: **Jill S  Vollmer; Robert D  Vollmer → Vollmer Excavation, Inc. → Foothill Granite LLC**

- 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:** Central Valley Asphalt → Foothill Granite LLC; 2010-05-10 to 2013-03-18; source msha-controller-operator-history
- **controller_controls_mine:** Gregory Douglas  Ross → Foothill Granite LLC; 2010-05-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gregory Douglas  Ross → Central Valley Asphalt; 2010-05-10 to 2013-03-18; source msha-controller-operator-history
- **operator_operates_mine:** Vollmer Excavation, Inc. → Foothill Granite LLC; 2013-03-19 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert D  Vollmer et al → Foothill Granite LLC; 2013-03-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert D  Vollmer et al → Vollmer Excavation, Inc.; 2013-03-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jill S  Vollmer et al → Vollmer Excavation, Inc.; 2013-03-19 to current/open; source msha-controller-operator-history