# Relationship history for MSHA mine 1300640

Current hierarchy: **B L Anderson Inc → B L Anderson Inc → Gateway Sand & Gravel**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** B L Anderson Inc → Gateway Sand & Gravel; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Acme Aggregates Company → Gateway Sand & Gravel; 1950-01-01 to 1983-07-18; source msha-controller-operator-history
- **controller_controls_mine:** W G Block Company Inc → Gateway Sand & Gravel; 1950-01-01 to 1983-07-18; source msha-controller-operator-history
- **controller_controls_operator:** W G Block Company Inc → Acme Aggregates Company; 1950-01-01 to 1983-07-18; source msha-controller-operator-history
- **operator_operates_mine:** B L Anderson Inc → Gateway Sand & Gravel; 1983-07-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** B L Anderson Inc → B L Anderson Inc; 1983-07-19 to current/open; source msha-controller-operator-history