# Relationship history for MSHA mine 0700075

Current hierarchy: **Stacey R Sizemore → Porters Sand & Gravel → Porter Sand Pit**

- 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:** Porters Sand & Gravel → Porter Sand Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Frank E  Porter → Porter Sand Pit; 1950-01-01 to 2026-01-13; source msha-controller-operator-history
- **controller_controls_operator:** Frank E  Porter → Porters Sand & Gravel; 1950-01-01 to 2026-01-13; source msha-controller-operator-history
- **controller_controls_mine:** Stacey R Sizemore → Porter Sand Pit; 2026-01-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stacey R Sizemore → Porters Sand & Gravel; 2026-01-14 to current/open; source msha-controller-operator-history