# Relationship history for MSHA mine 2401460

Current hierarchy: **Albert A  Schellinger → Schellinger Construction Co., Inc. → Carlson Wash Plant**

- 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

- **controller_controls_mine:** Albert A  Schellinger → Carlson Wash Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Carlson Sand & Gravel → Carlson Wash Plant; 1979-01-01 to 2007-04-11; source msha-controller-operator-history
- **controller_controls_mine:** Duane A  Carlson  et al → Carlson Wash Plant; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Duane A  Carlson  et al → Carlson Sand & Gravel; 1979-01-01 to 2007-04-11; source msha-controller-operator-history
- **operator_operates_mine:** Schellinger Construction Co., Inc. → Carlson Wash Plant; 2007-04-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Albert A  Schellinger → Schellinger Construction Co., Inc.; 2007-04-12 to current/open; source msha-controller-operator-history