# Relationship history for MSHA mine 4701791

Current hierarchy: **Kyle  Frank; Timothy  Frank → Frank Brothers Inc → PORTABLE UNIT #1 (HEWITT ROBBINS**

- 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

- **operator_operates_mine:** Frank Brothers Inc → PORTABLE UNIT #1 (HEWITT ROBBINS; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Donald E  Frank et al → PORTABLE UNIT #1 (HEWITT ROBBINS; 1950-01-01 to 2015-09-14; source msha-controller-operator-history
- **controller_controls_operator:** Donald E  Frank et al → Frank Brothers Inc; 1950-01-01 to 2015-09-14; source msha-controller-operator-history
- **controller_controls_mine:** Kyle  Frank et al → PORTABLE UNIT #1 (HEWITT ROBBINS; 2015-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kyle  Frank et al → Frank Brothers Inc; 2015-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Timothy  Frank et al → Frank Brothers Inc; 2015-09-15 to current/open; source msha-controller-operator-history