A total of 435 United States Geological Survey and United States Forest Service workers in Alaska were studied for serologic evidence of past infections with four arboviruses known or suspected to be human pathogens. Of the personnel tested, 36 (8.3%) had the neutralizing antibody to Jamestown Canyon but not snowshoe hare virus, 6 (1.4%) had the antibody to snowshoe hare but not Jamestown Canyon virus, 53 (12.2%) had the antibody to both viruses, 17 (3.9%) had the antibody to Northway virus, and 15 (3.4%) had the antibody to Klamath virus. The indices most significantly correlated with presence of the Jamestown Canyon and snowshoe hare antibodies were the amount of fieldwork (p less than 0.001 for both antibodies) and the duration of employment by the agencies (p less than 0.0001 for Jamestown Canyon and 0.004 for snowshoe hare). The antibody to the four arboviruses also correlated strongly with a history of travel in certain remote or wilderness areas in Alaska (p values ranged from less than 0.001 to 0.086).