# Relationship history for MSHA mine 2002901

Current hierarchy: **John S  Yerington II → Michiana Aggregate, Inc. → Hartman Fabco 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

- **operator_operates_mine:** Michiana Aggregate Inc → Hartman Fabco Plant; 1993-06-01 to 1994-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Ron  Smith → Hartman Fabco Plant; 1993-06-01 to 1994-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Ron  Smith → Michiana Aggregate Inc; 1993-06-01 to 1994-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Michiana Aggregate, Inc. → Hartman Fabco Plant; 1994-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John S  Yerington II → Hartman Fabco Plant; 1994-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John S  Yerington II → Michiana Aggregate, Inc.; 1994-07-01 to current/open; source msha-controller-operator-history