# Relationship history for MSHA mine 2800780

Current hierarchy: **Williams Tim E → Trans Mix Sand & Gravel Inc → Trans Mix Sand & Gravel Incorporated**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Trans-Mix Inc → Trans Mix Sand & Gravel Incorporated; 1950-01-01 to 1986-06-05; source msha-controller-operator-history
- **controller_controls_mine:** Williams Clyde → Trans Mix Sand & Gravel Incorporated; 1950-01-01 to 1986-06-05; source msha-controller-operator-history
- **controller_controls_operator:** Williams Clyde → Trans-Mix Inc; 1950-01-01 to 1986-06-05; source msha-controller-operator-history
- **operator_operates_mine:** Trans Mix Sand & Gravel Inc → Trans Mix Sand & Gravel Incorporated; 1986-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Williams Tim E → Trans Mix Sand & Gravel Incorporated; 1986-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Williams Tim E → Trans Mix Sand & Gravel Inc; 1986-06-06 to current/open; source msha-controller-operator-history