# Relationship history for MSHA mine 3502931

Current hierarchy: **Eric W  Coats → Shevlin Sand & Gravel LLC → Cake Pit**

- 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:** Deschutes Ready-Mix Sand & Gravel Company → Cake Pit; 1979-01-01 to 2001-10-15; source msha-controller-operator-history
- **controller_controls_mine:** Eric W  Coats et al → Cake Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eric W  Coats et al → Deschutes Ready-Mix Sand & Gravel Company; 1979-01-01 to 2001-10-15; source msha-controller-operator-history
- **operator_operates_mine:** Shevlin Sand & Gravel LLC → Cake Pit; 2001-10-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Eric W  Coats et al → Cake Pit; 2001-10-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eric W  Coats et al → Shevlin Sand & Gravel LLC; 2001-10-16 to current/open; source msha-controller-operator-history