The Canyon de Chelly was a sacred place for the Navajo. They believed that it would now be their strongest sanctuary, and 300 Navajo took refuge on the canyon rim, called Fortress Rock. They resisted Carson's invasion by building rope ladders and bridges, lowering water pots into a stream, and keeping quiet and out of sight. The 300 Navajo survived the invasion. In January 1864, Carson swept through the Canyon with his forces, including Captain Albert Pfeiffer. The thousands of peach trees in the canyon were cut down. Few Navajo were killed or captured. Carson's invasion, however, proved to the Navajo that the United States could invade their territory at any time. Many Navajo surrendered at Fort Defiance, Arizona.