# Relationship history for MSHA mine 2003312

Current hierarchy: **Brent  Gerken; Michael J  Gerken → Gerken Materials Inc. → Tecumseh Plant**

- 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

- **controller_controls_mine:** Jeffery J  Stansley et al → Tecumseh Plant; 1991-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sylvester Material Co Inc → Tecumseh Plant; 2005-02-22 to 2006-05-14; source msha-controller-operator-history
- **controller_controls_operator:** Jeffery J  Stansley et al → Sylvester Material Co Inc; 2005-02-22 to 2006-05-14; source msha-controller-operator-history
- **controller_controls_mine:** Jeffery J  Stansley et al → Tecumseh Plant; 2006-03-14 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Stansley Mineral Resources, Inc. → Tecumseh Plant; 2006-05-15 to 2012-08-21; source msha-controller-operator-history
- **controller_controls_operator:** Jeffery J  Stansley et al → Stansley Mineral Resources, Inc.; 2006-05-15 to 2012-08-21; source msha-controller-operator-history
- **controller_controls_mine:** Brent  Gerken et al → Tecumseh Plant; 2008-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jefferey J  Stansley et al → Tecumseh Plant; 2012-08-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** GS Materials, LLC → Tecumseh Plant; 2012-08-22 to 2017-12-14; source msha-controller-operator-history
- **controller_controls_operator:** Jefferey J  Stansley et al → GS Materials, LLC; 2012-08-22 to 2017-12-14; source msha-controller-operator-history
- **controller_controls_operator:** Brent  Gerken et al → GS Materials, LLC; 2012-08-22 to 2017-12-14; source msha-controller-operator-history
- **controller_controls_operator:** Richard B  Stansley Jr et al → GS Materials, LLC; 2012-08-22 to 2017-12-14; source msha-controller-operator-history
- **operator_operates_mine:** Gerken Materials Inc. → Tecumseh Plant; 2017-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brent  Gerken et al → Gerken Materials Inc.; 2017-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael J  Gerken et al → Gerken Materials Inc.; 2017-12-15 to current/open; source msha-controller-operator-history