# Relationship history for MSHA mine 3604673

Current hierarchy: **Chris J  Schiffer; Todd C  Schiffer → Schiffer Excavating Inc → Cooperstown Sand & Gravel**

- 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:** Tionesta Sand & Gravel Inc → Cooperstown Sand & Gravel; 1950-01-01 to 1983-11-09; source msha-controller-operator-history
- **controller_controls_mine:** Colas S A → Cooperstown Sand & Gravel; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Colas S A → Tionesta Sand & Gravel Inc; 1950-01-01 to 1983-11-09; source msha-controller-operator-history
- **operator_operates_mine:** Schiffer Excavating Inc → Cooperstown Sand & Gravel; 1983-11-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Todd C  Schiffer et al → Cooperstown Sand & Gravel; 1983-11-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Todd C  Schiffer et al → Schiffer Excavating Inc; 1983-11-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chris J  Schiffer et al → Schiffer Excavating Inc; 1983-11-10 to current/open; source msha-controller-operator-history