# Relationship history for MSHA mine 3601934

Current hierarchy: **Raymond Donald J & Eric Schramm → Laurie Enterprise Inc → Laurie Enterprises Breaker**

- 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:** Old Mill Coal Yard → Laurie Enterprises Breaker; 1950-01-01 to 1975-11-01; source msha-controller-operator-history
- **controller_controls_mine:** Old Mill Coal Yard → Laurie Enterprises Breaker; 1950-01-01 to 1975-11-01; source msha-controller-operator-history
- **controller_controls_operator:** Old Mill Coal Yard → Old Mill Coal Yard; 1950-01-01 to 1975-11-01; source msha-controller-operator-history
- **operator_operates_mine:** Laurie Enterprise → Laurie Enterprises Breaker; 1975-11-02 to 1978-08-09; source msha-controller-operator-history
- **controller_controls_mine:** Derr Robert L → Laurie Enterprises Breaker; 1975-11-02 to 1978-08-09; source msha-controller-operator-history
- **controller_controls_operator:** Derr Robert L → Laurie Enterprise; 1975-11-02 to 1978-08-09; source msha-controller-operator-history
- **operator_operates_mine:** Laurie Enterprise Inc → Laurie Enterprises Breaker; 1978-08-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Raymond Donald J & Eric Schramm → Laurie Enterprises Breaker; 1978-08-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Raymond Donald J & Eric Schramm → Laurie Enterprise Inc; 1978-08-10 to current/open; source msha-controller-operator-history