Comment: 8 pages, 2 figures, 1 tableThe Sturgis Motorcycle Rally that took place from August 7-16 was one of the largest public gatherings since the start of the COVID-19 outbreak. Over 460,000 visitors from across the United States travelled to Sturgis, South Dakota to attend the ten day event. Using anonymous cell phone tracking data we identify the home counties of visitors to the rally and examine the impact of the rally on the spread of COVID-19. Our baseline estimate suggests a one standard deviation increase in Sturgis attendance increased COVID-19 case growth by 1.1pp in the weeks after the rally.