# Relationship history for MSHA mine 4500920

Current hierarchy: **Dick  Larsen → Twin River Clay Inc → TWIN RIVERS CLAY, INC**

- 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:** Twin River Clay Inc → TWIN RIVERS CLAY, INC; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dick  Larsen et al → TWIN RIVERS CLAY, INC; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dick  Larsen et al → Twin River Clay Inc; 1950-01-01 to current/open; source msha-controller-operator-history