Navajo Nation and the Ute Mountain Ute Tribe Reservation, with the Ute Mountain tribal boundaries coinciding with Colorado's boundaries at the monument. Climate Located in the Colorado Plateau region of the Southwestern United States, the Four Corners Monument has a strong cold semi-arid climate (BSk) according to the Köppen climate classification system. Winters are cold but sunny, while summers are hot and dry. The record high temperature of has been observed five times, on June 19, 29 and 30, 1974, July 14, 2003, and July 21, 2005. The record low temperature of was observed on January 3, 1974. History The area now called Four Corners was initially American Indian land and beginning in the 16th century it was claimed by Spain as part of New Spain. After Mexico gained independence from Spain in 1821, the area was governed by Mexico until being ceded to the United States by the Treaty of Guadalupe Hidalgo in 1848 following the United States' victory in the Mexican–American War. The first boundary which would become part of the monument was set as part of the Compromise of 1850, which created the New Mexico Territory and Utah Territory. The border between the two territories was congressionally defined as the 37th parallel north by the 31st United States Congress. In 1861, the 36th United States Congress transferred land previously allocated to the Utah Territory to the newly created Colorado Territory. The Colorado Territory's southern border would remain as the 37th parallel north, but a new border—between the Colorado and Utah Territories—was declared to be the 32nd meridian west from Washington. This line was derived from the reference used at the time, the Washington meridian. In 1860, just prior to the outbreak of the American Civil War, a group of people in the southern portion of New Mexico Territory passed a resolution condemning the United States for creating such a vast territory with only a single, small government in place at Santa Fe. They claimed that by doing so, the U.S. had ignored the needs of the southern portion, left it without a functional system of law and order, and allowed the situation to deteriorate into a state of chaos and near-anarchy. The group declared secession from the United States and announced their intent to join the Confederate States of America under the name of the Arizona Territory. The U.S. Congress responded in 1863 by creating another Arizona