In the winter of 2020, Illinois suffered millions of dollars in coastal damage from abnormally strong waves. These waves were fueled by record high lake levels, a phenomenon expected to become increasingly likely under climate change. This paper examines the impact of climate change-induced lake level rise on beach access across the state. My mixed-methods approach combines spatial analysis of lake climate projections with legal analysis of their implications for beach access protections under the public trust doctrine. I find that up to sixty percent of existing beach spaces may be fully inundated by 2040. Furthermore, since existing public trust precedent assumes a stable lake level, it will be significantly challenged by rising water levels, leading to jurisdictional confusion for maintaining beach access even as beaches themselves steadily erode. Without significant policy intervention, Illinois may lose most of its Lake Michigan beaches.