The Four Corners Monument marks the quadripoint in the Southwestern United States where the states of Arizona, New Mexico, Utah meet. It is the only point in the United States shared by four states, leading to the area being named the Four Corners region; the monument marks the boundary between two semi-autonomous Native American governments, the Navajo Nation, which maintains the monument as a tourist attraction, the Ute Mountain Ute Tribe Reservation. The origins of the state boundaries marked by the monument occurred just prior to, during, the American Civil War, when the United States Congress acted to form governments in the area to combat the spread of slavery to the region; when the early territories were formed, their boundaries were designated along meridian and parallel lines. Beginning in the 1860s, these lines were marked; these early surveys included some errors, but so, the markers placed became the legal boundaries, superseding the written descriptions of geographical meridians and parallels.

This includes the Four Corners Monument, established as the corner of the four states. The monument is maintained as a tourist attraction by the Navajo Nation Parks and Recreation Department, it is an example of a political boundary, a tourist destination in its own right. The monument consists of a granite disk embedded with a smaller bronze disk around the point, surrounded by smaller, appropriately located state seals and flags representing both the states and tribal nations of the area. Circling the point, starting from north, the disk reads with two words in each state "Here meet in freedom under God four states". Around the monument, local Navajo and Ute artisans sell souvenirs and food. An admission fee is required to photograph the monument; the monument is a popular tourist attraction despite isolated location. As early as 1908, people traveled long distances to take pictures of family and friends at the monument in Twister-like poses, sitting on the disk, in a circle of friends or family around the disk, or for couples to kiss directly over the disk.

The monument is located on the Colorado Plateau west of U. S. Highway 160 40 miles southwest of Cortez, Colorado. In addition to the four states, two semi-autonomous American Indian tribal governments have boundaries at the monument, the Navajo Nation and the Ute Mountain Ute Tribe Reservation, with the Ute Mountain tribal boundaries coinciding with Colorado's boundaries at the monument. Located in the Colorado Plateau desert region of the Southwestern United States, The Four Corners Monument has a strong cold desert climate according to the Köppen climate classification system. Winters are cold but sunny, while summers are dry; the record high temperature of 105 °F has been observed five times, on June 19, 29 and 30, 1974, July 14, 2003, July 21, 2005. The record low temperature of −18 °F was observed on January 3, 1974; the area now called Four Corners was 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 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 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, 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 Territory with different, but overlapping boundaries; the Confederate boundaries split New Mexico along an east–west line, the 34th parallel north, allowing for a single state connection from Texas to the Colorado River. This would give the Confederacy access to the Pacific coast; the Union definition split New Mexico along a north–south line, the 32nd meridian west from Washington, which extended the boundary between Colorado and Utah southward. The Union plan became reality, this created the quadripoint at the modern Four Corners. After the split, New Mexico resembled its modern form, with only slight differences.

After the Civil War, efforts began to mark the actual borders. In 1868, the General Land Office had Ehud N. Darling survey and set markers along the border between the Colorado and New Mexico Territories. In 1875, another GLO surveyor, Chandler Robbins and marked the border between the Arizona and New Mexico Terr

Donald Tialavea Jr. is an American football offensive tackle, a free agent. He played college football at Utah State University, he signed with the Jacksonville Jaguars in 2014 as an undrafted free agent. Tialavea was a tight end prior to switching positions before the 2017 NFL season. Tialavea attended West Jordan High School in Utah. During his high school football career, he played on the offensive and defensive lines. In addition to being a three-year letterwinner in football, Tialavea was a three-year letterwinner in basketball and baseball. Tialavea appeared in 40 games for the Utah State Aggies, he ended his college career with five touchdowns. Tialavea was signed by the Jacksonville Jaguars after going undrafted in the 2014 NFL Draft, he was released on May 12, 2014. After being released by the Jaguars, Tialavea was signed to the Buffalo Bills practice squad on September 2, 2014, he was released by the Bills on September 30, 2014. Tialavea was signed to the Falcons' practice squad on November 24, 2015.

After spending two seasons on the practice squad, he was promoted to the active roster on December 22, 2016. In his NFL debut two days against the Carolina Panthers, Tialavea caught a touchdown for his only reception of the day. Tialavea was inactive for the Falcons' 34-28 overtime loss to the New England Patriots in the Super Bowl. On September 1, 2017, Tialavea was released by the Falcons. On September 20, 2017, Tialavea was signed to the Chicago Bears' practice squad, he was released on September 26, 2017. He was re-signed on December 27, 2017. D. J.'s parents are Tami Tialavea. He has two sisters. Tialavea graduated from Utah State with an interdisciplinary studies degree with a focus in business management and physical education administration. D. J. is an Eagle Scout. Utah State Aggies bio Atlanta Falcons bio

Viktor Vladimirovich Wagner Vagner was a Russian mathematician, best known for his work in differential geometry and on semigroups. Wagner was born in Saratov and studied at Moscow State University, where Veniamin Kagan was his advisor, he became the first geometry chair at Saratov State University. He received the Lobachevsky Medal in 1937. Wagner was awarded "the Order of Lenin, the Order of the Red Banner, the title of Honoured Scientist RSFSR. Moreover, he was accorded that rarest of privileges in the USSR: permission to travel abroad."Wagner is credited with noting that the collection of partial transformations on a set X forms a semigroup P T X, a subsemigroup of the semigroup B X of binary relations on the same set X, where the semigroup operation is composition of relations. "This simple unifying observation, an important psychological hurdle, is attributed by Schein to V. V. Wagner." Inverse semigroup Heap B. M. Schein. "Obituary: Viktor Vladimirovich Vagner". Semigroup Forum. 28: 189–200.

Doi:10.1007/BF02676643. Viktor Wagner at the Mathematics Genealogy Project Wagner, V. V.. "Обобщенные группы". Doklady Akademii Nauk SSSR. 84: 1119–1122. Wagner's Biography – in Russian