# Relationship history for MSHA mine 4500087

Current hierarchy: **Don  Merlino; Gary  Merlino → Stoneway Rock & Recycling Co → Sunset Quarry**

- 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:** Eastside Rock Products → Sunset Quarry; 1950-01-01 to 1991-11-19; source msha-controller-operator-history
- **controller_controls_mine:** Richard  Schroeder → Sunset Quarry; 1950-01-01 to 1995-02-23; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Schroeder → Eastside Rock Products; 1950-01-01 to 1991-11-19; source msha-controller-operator-history
- **controller_controls_mine:** Don  Merlino et al → Sunset Quarry; 1988-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Stoneway Rock & Recycling Co → Sunset Quarry; 1991-11-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Don  Merlino et al → Stoneway Rock & Recycling Co; 1991-11-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gary  Merlino et al → Stoneway Rock & Recycling Co; 1991-11-20 to current/open; source msha-controller-operator-history