Suddenly, the volcano erupts. Molten lava pours toward the ice. If the lava were hot enough, it would melt its way through the glacial ice like a hot knife through butter, then follow the path of least resistance–flowing down into the valleys. As it turned out though, the lava wasn’t hot enough. Mount Rainier’s lava was only able to melt through the thinnest parts of the glacier–those parts that were over ridges and hilltop spines. When the glacier retreated, it left behind the geography we see today: Hardened lava flowing along hilltops, and valleys free of lava flows. Is there a moral to this story of patient ice and fiery lava? We can’t say, but the history seems to be written clearly enough, in flowing lines down the slopes of Mount Rainier.