This valuable book is an excellent overview of long-term archaeological investigations in the valley that remains at the forefront of studies on the First Americans.   In southwest Nebraska, a stretch of Medicine Creek approximately 20 kilometers long holds a remarkable concentration of both late Paleoindian and late prehistoric sites. Unlike several nearby similar and parallel streams that drain the divide between the Platte and Republican Rivers, Medicine Creek has undergone 70 years of archaeological excavations that reveal a long occupation by North America's earliest inhabitants.   Donna Roper has collected the written research in this volume that originated in a conference celebrating the 50th anniversary of the 1947 River Basin Survey. In addition to 12 chapters reviewing the long history of archaeological investigations at Medicine Creek, the volume contains recent analyses of and new perspectives on old sites and old data. Two of the sites discussed are considered for pre-Clovis status because they show evidence of human modification of mammoth faunal remains in the late Pleistocene Age. Studies of later occupation of Upper Republican phase sites yield information on the lifeways of Plains village people.   Presented by major investigators at Medicine Creek, the contributions are a balanced blend of the historical research and the current state-of-the-art work and analysis. Roper's comprehensive look at the archaeology, paleontology, and geomorphology at Medicine Creek gives scientists and amateurs a full assessment of a site that has taught us much about the North American continent and its early people.