# Relationship history for MSHA mine 1201902

Current hierarchy: **Vigo Coal Company Incorporated → Koester Mining Corp → Callisto Coal Preparation 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:** Vigo Coal Company Incorporated → Callisto Coal Preparation Plant; 1975-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Wabash Valley Energy Inc → Callisto Coal Preparation Plant; 1982-09-01 to 1984-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Heitman James R → Callisto Coal Preparation Plant; 1982-09-01 to 1984-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Heitman James R → Wabash Valley Energy Inc; 1982-09-01 to 1984-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Chieftain Coal Company Inc → Callisto Coal Preparation Plant; 1984-07-01 to 1988-08-14; source msha-controller-operator-history
- **controller_controls_mine:** Texas Lignite Corp → Callisto Coal Preparation Plant; 1984-07-01 to 1988-08-14; source msha-controller-operator-history
- **controller_controls_operator:** Texas Lignite Corp → Chieftain Coal Company Inc; 1984-07-01 to 1988-08-14; source msha-controller-operator-history
- **operator_operates_mine:** Koester Mining Corp → Callisto Coal Preparation Plant; 1988-08-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vigo Coal Company Incorporated → Koester Mining Corp; 1988-08-15 to current/open; source msha-controller-operator-history