# Relationship history for MSHA mine 2102787

Current hierarchy: **Hegstrom Fred → Fred Hegstrom Gravel & Rock → Hegstrom 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:** Long Lake Rock & Gravel Inc → Hegstrom Pit; 1980-06-01 to 1983-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Gabrielson George → Hegstrom Pit; 1980-06-01 to 1983-11-15; source msha-controller-operator-history
- **controller_controls_operator:** Gabrielson George → Long Lake Rock & Gravel Inc; 1980-06-01 to 1983-11-15; source msha-controller-operator-history
- **operator_operates_mine:** Fred Hegstrom Gravel & Rock → Hegstrom Pit; 1983-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hegstrom Fred → Hegstrom Pit; 1983-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hegstrom Fred → Fred Hegstrom Gravel & Rock; 1983-11-16 to current/open; source msha-controller-operator-history