The geology of southern New Mexico and west Texas represents over a billion years of earth's history. Evidence of events such as explosive eruptions of great volcanoes, uplift and erosion of ancient mountains, and deposition of sediment in subtropical seas is available for those who know how to read the rocks. This guide for non-specialists not only provides the necessary background for comprehension but also a guide to local features. Part I explains the basic principles of geology, including the origin of rocks, geologic time, rock deformation, and plate tectonics. Part II divides the geologic history of the region into eight major events and illustrates both the rock strata produced by each event and the ancient geography of the era. Part III contains twenty-two field trips to view geologic history, mostly in easily accessible natural outcrops. Natives and visitors alike will find that this clearly written and well-illustrated book contributes to a greater appreciation of the unique landscape of the southwest.

In the course of the hundreds of Rio Chama rafting trips that we've logged during the last 30 years, none of us has ever had a bad trip. Such is the magic of the Rio Chama. No matter the weather, the water level, the season, the crowded Big Eddy boat ramp on a blistering Sunday afternoon, or even the coffee forgotten at home, the Rio Chama remains "The People's River." Its stunning beauty, plus its exceptional camping, user-friendly whitewater, and mostly predictable flows, combine to create one of the Southwest's premiere, multi-day, river running experiences.The spectacular, towering canyon walls of the Wild & Scenic section through the remote Chama River Canyon Wilderness is New Mexico's own "Grand Canyon." The geology of the Rio Chama is so exceptional that this river is ideally suited for a river guide with a geological theme. And so, following the release of the Rio Grande geologic river guide in 2011, we turned our (part-time) attention to the Rio Chama. Although most Rio Chama recreation is focused on the El Vado to Big Eddy stretch, thedecision was easily made to include the entire boatable section, from the highlands in Colorado to the confluence with the Rio Grande, as each section of the river displays its own visual spectacles and assortment of adventures. Plus, the geology is magnificent and diverse along the entire length of the river.

This reader-friendly exploration along what was once New Mexico State Highway 44, now redesignated the southern part of federal highway US-550, melds both the human and geologic history along the major transportation corridor connecting the Rio Grande Valley in central New Mexico with the San Juan River Valley in the far northwestern part of the state. Numerous illustrations portray the region's geology in a form intelligible and interesting to the non-geologist. The basic understanding of the landscape thus provides the scaffolding to support the stories of the interesting people who figure in the history along "Old 44." The book aims to provide a view of the highway and its environs in an entirely new way and to make history and geology seem a natural and necessary pairing. DIRK VAN HART earned his Bachelor's and Master's degrees in geology, and in 1965 began a professional career as a petroleum geologist. During the next two decades the gypsy life of the geologist took him to Oklahoma, Texas, California, Guatemala, and Ecuador. In 1986 a career change led him to move his family to Albuquerque, New Mexico where he engaged in contract geological projects in Italy and Belize, and for a short while taught high-school science. In 1994 he joined a team effort to characterize the geology of Kirtland Air Force Base in Albuquerque as a contractor for Sandia National Laboratories. He is now retired.