# Relationship history for MSHA mine 3608844

Current hierarchy: **Daniel R  Hawbaker → Glenn O Hawbaker Inc → Lawrenceville Aggregate Plant #20**

- 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

- **controller_controls_mine:** Daniel R  Hawbaker  et al → Lawrenceville Aggregate Plant #20; 1983-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** E W R Gravel Pit → Lawrenceville Aggregate Plant #20; 2000-03-01 to 2002-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Fred  Robbins → Lawrenceville Aggregate Plant #20; 2000-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Fred  Robbins → E W R Gravel Pit; 2000-03-01 to 2002-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Glenn O Hawbaker Inc → Lawrenceville Aggregate Plant #20; 2002-05-01 to 2002-06-10; source msha-controller-operator-history
- **controller_controls_operator:** Daniel R  Hawbaker  et al → Glenn O Hawbaker Inc; 2002-05-01 to 2002-06-10; source msha-controller-operator-history
- **operator_operates_mine:** E W R Gravel Pit → Lawrenceville Aggregate Plant #20; 2002-06-11 to 2007-05-28; source msha-controller-operator-history
- **controller_controls_operator:** Fred  Robbins → E W R Gravel Pit; 2002-06-11 to 2007-05-28; source msha-controller-operator-history
- **operator_operates_mine:** Glenn O Hawbaker Inc → Lawrenceville Aggregate Plant #20; 2007-05-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Daniel R  Hawbaker  et al → Glenn O Hawbaker Inc; 2007-05-29 to current/open; source msha-controller-operator-history