# Relationship history for MSHA mine 2103477

Current hierarchy: **Raymond E  Koch; Kathy R  Koch → Ray's Gravel, LLC → Gardner Denver**

- 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

- **operator_operates_mine:** Ray's Gravel, LLC → Gardner Denver; 2005-03-31 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Raymond E  Koch et al → Gardner Denver; 2005-03-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Raymond E  Koch et al → Ray's Gravel, LLC; 2005-03-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kathy R  Koch et al → Ray's Gravel, LLC; 2005-03-31 to current/open; source msha-controller-operator-history