Mastodonia Author:Clifford D. Simak Asa Steele was a paleontogy instructor from a small western college - and just about fed-up with it. He returned home to rural Wisconsin on sabatical to think things over - - and to investigate what he thought might be the site of a crashed UFO that he remembered as a boy. Like so much else, it was still there unchanged. The fragments that he e... more »scavated came back from the university lab as belonging to an unknown alloy with extraordinary properties. Yet there was nothing else that really proved an extraterrestrial origin. That is, until his dog started to bring back dinosaur bones and other artifacts from the gateway that the ship had punched through the space-time fabric ....« less
Time-traveling turns into big business and big trouble when a casual walk down a farm path in a quiet Wisconsin town leads an archeologist into the Pleistocene era and he uncovers an interstellar mystery from before recorded time...