# Relationship history for MSHA mine 3003166

Current hierarchy: **Roy K  Howell → R. K. Howell Gravel Products → R. K. Howell Gravel Products**

- 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:** Smith Sand & Gravel → R. K. Howell Gravel Products; 1996-07-01 to 2006-03-19; source msha-controller-operator-history
- **controller_controls_mine:** Peter  Smith → R. K. Howell Gravel Products; 1996-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Peter  Smith → Smith Sand & Gravel; 1996-07-01 to 2006-03-19; source msha-controller-operator-history
- **operator_operates_mine:** R. K. Howell Gravel Products → R. K. Howell Gravel Products; 2006-03-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Roy K  Howell → R. K. Howell Gravel Products; 2006-03-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roy K  Howell → R. K. Howell Gravel Products; 2006-03-20 to current/open; source msha-controller-operator-history