In recent decades, conservation planning that is organized and funded by international agencies has embraced market-based mechanisms to promote sustainable landscapes across the globe. Costa Rica has embraced these mechanisms, offering itself as a laboratory for sustainable development initiatives that purportedly intertwine human and environmental well-being. The effectiveness of these market-based mechanisms is little understood, in part because academics and policy analysts seldom question how conservation markets intersect with the human values that are their intended targets. In this dissertation, I analyze how market-based conservation mechanisms, particularly nature tourism and payments for environmental services, engage with landowner values for conservation land uses in the Bellbird Biological Corridor of Costa Rica, and the extent to which these mechanisms effectively foster sustainability. I employ mixed methods, combining ethnography with a stated choice experiment and spatial analysis to triangulate the relationship between landowner values and conservation land uses in the study area. I find that though forest has regrown throughout the study area during the last few decades, market-based mechanisms do not appear to be directly responsible for this regrowth. On the contrary, the particular market-based mechanisms analyzed seem to impede rather than promote sustainability because they encourage some aspects of environmental health and undermine others. Analysis of landowner values indicates that these market-based mechanisms are poorly aligned with conservation values in the study area, and they may reinforce a simplistic, monetary view of the environment that runs counter to the long-term goals of sustainability. My findings contribute to literature in anthropology that examines the relationship between environmental markets and sustainability, as well as to interdisciplinary conservation literature examining policy efficacy. This research paves the way for further exploration of the impacts of market-based conservation policies on conservation values.