Divergent selection across heterogeneous landscapes can favor the evolution of locally adapted ecotypes. Contemporary climate change is simultaneously modifying multiple abiotic and biotic agents of selection, likely leading to growing discrepancies between current and optimal phenotypes. My lab evaluates the hypotheses that novel selection imposed by climate change shifts fitness landscapes, disrupts long-standing patterns of local adaptation, and leads to widespread maladaptation. In this talk, I will examine the ecological and evolutionary consequences of climate change for Boechera stricta, a mustard plant native to the Rocky Mountains. To do so, I first explore adaptation to contemporary and historical climates by analyzing fitness and phenotypes in five common gardens arrayed across an elevational gradient around the Rocky Mountain Biological Laboratory (Gothic, Colorado, USA). Genetic clines in functional traits can reflect adaptive responses to selection that varies over large spatial scales, and we have found extensive evidence for clinal variation in phenological, functional and physiological traits. I will then document on shifts in flowering phenology mediated by climate change from the 1970s to the present. Finally, I will present data from our climatic manipulations to interrogate the eco-evolutionary consequences of climate change.