# Relationship history for MSHA mine 3304597

Current hierarchy: **Brent  Gerken; Michael J  Gerken → Gerken Materials Inc. → Defiance 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Michael J  Gerken et al → Defiance Plant; 2008-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** K. C. Sand & Gravel LLC → Defiance Plant; 2008-05-05 to 2012-07-09; source msha-controller-operator-history
- **controller_controls_mine:** David J  Karlstadt et al → Defiance Plant; 2008-05-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David J  Karlstadt et al → K. C. Sand & Gravel LLC; 2008-05-05 to 2012-07-09; source msha-controller-operator-history
- **controller_controls_operator:** Jay A  Crites et al → K. C. Sand & Gravel LLC; 2008-05-05 to 2012-07-09; source msha-controller-operator-history
- **operator_operates_mine:** Lacuna Sand and Gravel LLC → Defiance Plant; 2012-07-10 to 2025-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Scott A  Sidle et al → Defiance Plant; 2012-07-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Scott A  Sidle et al → Lacuna Sand and Gravel LLC; 2012-07-10 to 2025-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Gerken Materials Inc. → Defiance Plant; 2026-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael J  Gerken et al → Gerken Materials Inc.; 2026-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brent  Gerken et al → Gerken Materials Inc.; 2026-01-01 to current/open; source msha-controller-operator-history