This document is the diary of Lieutenant Colonel Juan Bautista de Anza while on a military expedition to find and destroy Cuchanec Comanche Chief Cuerno Verde (Green Horn), who had been exacting terrible destruction on the Spanish settlements of New Mexico. The expedition left Santa Fe with 600 men on August 15, 1779. Joined a few days later by 200 Yutas (Utes) and Apaches, the expedition numbered 800 men and close to 2500 horses. Following a route unfamiliar to the Comanches and traveling at night by the light of the full moon across the broad San Luis Valley, Anza was able to surprise Cuerno Verde on the front range of the Great Plains near present-day Rye, Colorado. In the ensuing battle, Cuerno Verde, his son, and four other chiefs were killed while the Spaniards sustained only a couple of minor wounds. As they returned to Santa Fe on September 10, 1779, the stage was now set for the establishment of peace between the Spaniards and the warring Comanches and Utes. Because of the battle and the peace which followed, three mountains of Colorado today bear the names of the leaders of the combatants. A mountain west of Rye, Colorado, called Green Horn Mountain, rises above 12,000 feet. One east of Mineral Hot Springs and another east of the town of San Luis are named in honor of Juan Bautista de Anza and rise above 13,000 feet.