# Relationship history for MSHA mine 3608775

Current hierarchy: **Robert A  Housel; Richard C  Masters → Red Oak Sand & Gravel, LLC → RED OAK SAND & GRAVEL**

- 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:** Red Oak Sand & Gravel, LLC → RED OAK SAND & GRAVEL; 1999-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Richard W  Masters et al → RED OAK SAND & GRAVEL; 1999-01-01 to 2018-12-30; source msha-controller-operator-history
- **controller_controls_operator:** Richard W  Masters et al → Red Oak Sand & Gravel, LLC; 1999-01-01 to 2018-12-30; source msha-controller-operator-history
- **controller_controls_operator:** Robert A  Housel et al → Red Oak Sand & Gravel, LLC; 1999-01-01 to 2018-12-30; source msha-controller-operator-history
- **controller_controls_mine:** Richard C  Masters et al → RED OAK SAND & GRAVEL; 2018-12-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard C  Masters et al → Red Oak Sand & Gravel, LLC; 2018-12-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert A  Housel et al → Red Oak Sand & Gravel, LLC; 2018-12-31 to current/open; source msha-controller-operator-history