# Relationship history for MSHA mine 4502189

Current hierarchy: **Lance  Despain → Mt Si Quarry SMM → Mt Si 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:** Stoen Construction Company → Mt Si Quarry; 1950-01-01 to 1984-01-24; source msha-controller-operator-history
- **controller_controls_mine:** Stoen Milo & Glen → Mt Si Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stoen Milo & Glen → Stoen Construction Company; 1950-01-01 to 1984-01-24; source msha-controller-operator-history
- **controller_controls_mine:** Richard  Schroeder → Mt Si Quarry; 1950-01-01 to 1995-02-23; source msha-controller-operator-history
- **operator_operates_mine:** Eastside Rock Products → Mt Si Quarry; 1984-01-25 to 1995-02-23; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Schroeder → Eastside Rock Products; 1984-01-25 to 1995-02-23; source msha-controller-operator-history
- **operator_operates_mine:** Mt Si Quarry Inc → Mt Si Quarry; 1995-02-24 to 2025-02-05; source msha-controller-operator-history
- **controller_controls_mine:** Thomas P Weber → Mt Si Quarry; 1995-02-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas P Weber → Mt Si Quarry Inc; 1995-02-24 to 2025-02-05; source msha-controller-operator-history
- **operator_operates_mine:** Mt Si Quarry SMM → Mt Si Quarry; 2025-02-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lance  Despain → Mt Si Quarry; 2025-02-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lance  Despain → Mt Si Quarry SMM; 2025-02-06 to current/open; source msha-controller-operator-history