A social survey was conducted in the Fernan Lake watershed in Idaho to understand how people interact with the landscape around them. Blue-green algae growth occurs naturally, but human activities can significantly increase the frequency of blooms. The Idaho Department of Environmental Quality has identified excess amounts of phosphorus as the driver of the recurrent algae blooms in Fernan Lake. Some types of blue-green algae produce cyanotoxins which can threaten human and animal health, thus diminishing the use and enjoyment of the lake. This survey assessed human values and perceptions surrounding watershed use and water quality. The Fernan Lake watershed is comprised of all the land that eventually drains to the lake and includes all properties from the ridge tops to the valley. All households in the Fernan Lake watershed received the residential survey and all undeveloped property owners received the undeveloped property owner survey. The survey was conducted from March 2014 and all participants were instructed to return the survey by April 1, 2014. This data set contains the survey materials mailed to participants, survey data, and a collection of summarized survey results. During this same time, in-depth interviews were simultaneously conducted with residents of the Fernan Lake watershed. This data set contains the full transcripts of interview participants who waived confidentiality. Interview data was summarized by node (i.e., a term or idea expressed during the interview) and congruent node (i.e., a grouping of thematically similar nodes).