# Relationship history for MSHA mine 1300703

Current hierarchy: **Zeien Tom → Tom Zeien Sand & Gravel → Tom Zeien 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Joe Zeien Sand & Gravel → Tom Zeien Sand & Gravel; 1950-01-01 to 1979-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Zeien Joe → Tom Zeien Sand & Gravel; 1950-01-01 to 1979-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Zeien Joe → Joe Zeien Sand & Gravel; 1950-01-01 to 1979-01-31; source msha-controller-operator-history
- **operator_operates_mine:** Tom Zeien Sand & Gravel → Tom Zeien Sand & Gravel; 1979-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Zeien Tom → Tom Zeien Sand & Gravel; 1979-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Zeien Tom → Tom Zeien Sand & Gravel; 1979-02-01 to current/open; source msha-controller-operator-history