# Relationship history for MSHA mine 2700362

Current hierarchy: **Kenneth  Heffron → Heffron Materials-Div/Heffron Asphalt Corp → Heffron Materials-Div/Heffron Asphalt**

- 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:** Kenneth  Heffron → Heffron Materials-Div/Heffron Asphalt; 1986-02-19 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Heffron Materials-Div/Heffron Asphalt Corp → Heffron Materials-Div/Heffron Asphalt; 2001-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kenneth  Heffron → Heffron Materials-Div/Heffron Asphalt Corp; 2001-01-01 to current/open; source msha-controller-operator-history