Encompassing nearly seven thousand acres amid the woodlands of the Sangre de Cristo Mountains in northern New Mexico, the land that is now Pecos National Historical Park has witnessed thousands of years of cultural history stretching back to the Native peoples who long ago inhabited the pueblos of Pecos, then known as Cicuye. Once a trading center where Pueblo Indians, Spanish soldiers and settlers, and Plains Indians encountered one another, not always peacefully, Pecos was a stop on the Santa Fe Trail in the early 1800s and, later, on the first railroad in New Mexico. It was the site of a critical Civil War battle and in the twentieth century became a tourist destination. This book tells the story of how, over five centuries, cultures and peoples converged at Pecos and transformed its environment, ultimately shaping the landscape that greets park visitors today. Spanning the period from 1540, when Spaniards first arrived, into the twenty-first century, Crossroads of Change focuses on the history of the natural and historic resources Pecos National Historical Park now protects and interprets: the ruins of Pecos Pueblo and a Spanish mission church, a stage stop along the Santa Fe Trail, the Civil War battlefield of Glorieta Pass, a twentieth-century cattle ranch, and the national park itself. In an engaging style, authors Cori Knudten and Maren Bzdek detail the transformations of Pecos over time, often driven by the collision of different cultures, such as that between the Franciscan friars and Pecos Indians in the seventeenth century, and by the introduction of new animals, crops, and agricultural practices—but also by the natural forces of fire, drought, and erosion. Located on a natural trade route, Pecos has long served as a portal between different cultures and environments. Documenting this transformation over the ages, Crossroads of Change also, perhaps, shows us Pecos National Historical Park as a portal to the future.