McPhee spent twenty years riding shotgun with geologists up and down Interstate 80, pulling over at roadcuts, and this is his four books on the subject plus a fifth chunk stacked into one. It won the Pulitzer in 1999. He starts in Jersey with Ken Deffeyes and heads west, to Nevada, where the whole basin and range is quietly pulling itself apart. Wyoming with Dave Love, a rancher’s kid turned geologist who knew that country the way you know your own yard. California, which is mostly a pile of rock that drifted in and stuck. Then the old, cold stone under the Midwest that hasn’t done much of anything in a billion years. Each book is one geologist thinking out loud while McPhee keeps up. It’s a whole lot of rocks, maybe too many for some, but your understanding of deep time will linger long after you’ve forgotten basalt from gneiss.