One of the fundamental principles of geomorphology posits that water always flows downstream, such that rivers are expected to occupy topographic lows. Yet, on the island of Fogo, Cape Verde, many streams occur above local minima. These higher-elevation streams occupy lava channels, suggesting that channel properties may govern runoff pathways. I am documenting streams formed in lava channels on Fogo using remote sensing, field study, and laboratory experiments. Because Fogo is young, basaltic, sparsely vegetated, and arid, it provides an exceptional Mars analog. Understanding the role of lava channel properties in shaping ephemeral streams offers insight into the hydroclimatic history of basaltic terrains on Mars.