INTRODUCTION. The Sedona-Oak Creek Canyon area offers some of the most unique and spectacular geologic features in northern Arizona. Because of the relatively sparse vegetation most of these features are easy to recognize and photograph. Some of these geologic features are common on the Colorado Plateau of northern Arizona, western Colorado, southern Utah, and northeastern New Mexico. Others occur in many other parts of the American Southwest. This booklet is your field guide to the geology of this magnificent landscape of red rock pinnacles, buttes, mesas and canyons. All of the geologic features described in the text can be reached by short walks from Highways 89A and 79, Road 78, and from U.S. Forest Service roads. This booklet is written for the visitor who has an interest in geology, but who may not have had formal training in the subject. It may also help assure that the visiting geologist does not overlook some of the features described.