# Relationship history for MSHA mine 2301119

Current hierarchy: **Gregory  Schroeder; Gus  Zinn; Kasey  Graham → Fischer Materials LLC → Fischer Materials**

- 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

- **operator_operates_mine:** Dunstan & Yows Inc → Fischer Materials; 1950-01-01 to 1985-03-11; source msha-controller-operator-history
- **controller_controls_mine:** Emmett W  Dunstan → Fischer Materials; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Emmett W  Dunstan → Dunstan & Yows Inc; 1950-01-01 to 1985-03-11; source msha-controller-operator-history
- **operator_operates_mine:** Fischer Materials Co Inc → Fischer Materials; 1985-03-12 to 2025-10-31; source msha-controller-operator-history
- **controller_controls_mine:** John P  Fischer → Fischer Materials; 1985-03-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John P  Fischer → Fischer Materials Co Inc; 1985-03-12 to 2025-10-31; source msha-controller-operator-history
- **operator_operates_mine:** Fischer Materials LLC → Fischer Materials; 2025-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gus  Zinn et al → Fischer Materials; 2025-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gus  Zinn et al → Fischer Materials LLC; 2025-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gregory  Schroeder et al → Fischer Materials LLC; 2025-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kasey  Graham et al → Fischer Materials LLC; 2025-11-01 to current/open; source msha-controller-operator-history