Utah has been inhabited for thousands of years by various indigenous groups such as the ancient Puebloans, Navajo and Ute. The Spanish were the first Europeans to arrive in the mid-16th century, though the region's difficult geography and harsh climate made it a peripheral part of New Spain and later Mexico. Even while it was Mexican territory, many of Utah's earliest settlers were American, particularly Mormons fleeing marginalization and persecution from the United States. Following the Mexican–American War in 1848, the region was annexed by the U.S., becoming part of the Utah Territory, which included what is now Colorado and Nevada. Disputes between the dominant Mormon community and the ...