The McMurdo Dry Valleys are one of the coldest and driest deserts on Earth, yet they are home to a series of perennially ice-covered lakes that sustain unique microbial ecosystems. During my field seasons with the McMurdo Dry Valleys Long-Term Ecological Research (LTER) team, I studied the physical and biological limnology of these unique lakes. The Dry Valleys are key analogs for icy extraterrestrial environments, offering critical insight into how life might persist beneath ice sheets on Mars or the subsurface oceans of icy moons.