# Relationship history for MSHA mine 2003447

Current hierarchy: **Brent  Gerken; Michael J  Gerken → Gerken Materials Inc. → Round Lake Sand and Gravel West Plt**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Michael J  Gerken et al → Round Lake Sand and Gravel West Plt; 2008-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Woodstock Aggregate, LLC → Round Lake Sand and Gravel West Plt; 2010-08-27 to 2015-01-11; source msha-controller-operator-history
- **controller_controls_mine:** Joseph M  Gentner → Round Lake Sand and Gravel West Plt; 2010-08-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joseph M  Gentner → Woodstock Aggregate, LLC; 2010-08-27 to 2015-01-11; source msha-controller-operator-history
- **operator_operates_mine:** Gerken Materials Inc. → Round Lake Sand and Gravel West Plt; 2015-01-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael J  Gerken et al → Gerken Materials Inc.; 2015-01-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brent  Gerken et al → Gerken Materials Inc.; 2015-01-12 to current/open; source msha-controller-operator-history