This volume grew out of a symposium titled: “The origin of Mima mounds and similar micro-relief features: Multidisciplinary perspectives,” and an associated similarly themed field trip, both held at the Geological Society of America Annual Meetings, Houston, Texas, 4–9 October 2008. Five of the eight papers in that symposium were expanded for inclusion in this volume; with one nonsymposium paper added later (Johnson and Johnson, Chapter 6). The volume was invited and encouraged by the editors of GSA Special Papers to be one of their series. In regard to soil mounds, the symposium was timely for several reasons.