# Relationship history for MSHA mine 0301799

Current hierarchy: **Philip D  Lentz; Robert G  Lentz → Lentz Sand & Gravel → Lentz 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:** Lentz Construction Company Inc → Lentz Sand & Gravel; 1998-07-01 to 2004-10-25; source msha-controller-operator-history
- **controller_controls_mine:** Robert G  Lentz et al → Lentz Sand & Gravel; 1998-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert G  Lentz et al → Lentz Construction Company Inc; 1998-07-01 to 2004-10-25; source msha-controller-operator-history
- **controller_controls_operator:** Philip D  Lentz et al → Lentz Construction Company Inc; 1998-07-01 to 2004-10-25; source msha-controller-operator-history
- **operator_operates_mine:** Lentz Sand & Gravel → Lentz Sand & Gravel; 2004-10-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert G  Lentz et al → Lentz Sand & Gravel; 2004-10-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert G  Lentz et al → Lentz Sand & Gravel; 2004-10-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Philip D  Lentz et al → Lentz Sand & Gravel; 2004-10-26 to current/open; source msha-controller-operator-history