Decisions about dams, like other environmental conflicts, involve complex trade-offs between different water uses with varying human and ecological impacts, have significant impacts on public resources, and involve many stakeholders with diverse and often conflicting interests. Given the many upcoming dam decisions in New England and across the United States, an improved understanding of public preferences about dam decisions is needed to steward resources in the public interest. This research asks (1) What does the public want to see happen with dams? and (2) How do public preferences regarding dam removal vary with demography and politics? We address these questions using data from three random sample statewide telephone polls conducted in New Hampshire over 2018 that asked people for their preferences concerning dam removal versus maintaining dams for specific benefits—property values, hydropower generation, industrial history, or recreation. Respondent age, education, gender, and political party were tested among the possible predictors. We find that majorities (52% or 54%) of respondents favor removing dams rather than keeping them for industrial history or property values, and a plurality (43%) favor removal over keeping them for recreation. A plurality (46%) prefer keeping dams, however, if they are used to generate hydropower. Respondent background characteristics and political identity affect these preferences in ways resembling those for many other environment-related issues: women, young or middle-aged individuals, and political liberals or moderates (Democrats or independents) more often support dam removal. Education, on the other hand, has no significant effects. The results quantify levels of general public support for dam removal in New England, illustrating the use of public opinion polling to complement input from public meetings and guide decisions. More broadly, they contribute a new topic to existing scholarship on the social bases of environmental concern.