An outbreak of gastroenteritis was associated with a law enforcement meeting and banquet that was held in Douglas, Wyoming. Participants attended trainings at the Wyoming Law Enforcement Academy (WLEA) and ate at a banquet provided by a local restaurant. One case patient tested positive for norovirus genogroup II. The epidemiologic investigation revealed that both direct and indirect (through food, beverage, or environmental surfaces) and person-to-person transmission propagated the infection. One participant and one beverage-handling employee were ill prior to the commencement of the meeting.