1,2; Haley Wienkes, MPH1; Jacob Garfin1; Xiong Wang, DVM, PhD1; Kelley Vilen, MPH1; Kirk E. Smith, DVM, PhD1; Stacy Holzbauer, DVM1,3; Matthew Plumb, MS1; Kelly Pung1; Carlota Medus, PhD1; Joseph D.
Yao, MD4; Matthew J. Binnicker, PhD4; Andrew C. Nelson, MD, PhD5; Sophia Yohe, MD5; Kathryn Como-Sabetti, MPH1; Kris Ehresmann, MPH1; Ruth Lynfield, MD1; Richard Danila, PhD1 (View author affiliations)Gatherings present an opportunity for rapid spread of COVID-19.Following a 10-day motorcycle rally in South Dakota attended by approximately 460,000 persons, 51 confirmed primary event-associated cases, 21 secondary cases, and five tertiary cases were identified in Minnesota residents.