1. New Mexico became a state: August 20, 1912 marks the day that New Mexico officially became the 47th state in the United States. It had previously been a territory, but statehood was granted by Congress earlier that year.

2. First nuclear test: On August 20, 1945, the world's first nuclear test was conducted at the Alamogordo Bombing Range, located in present-day White Sands Missile Range. The test, dubbed "Trinity," was part of the Manhattan Project and marked a major milestone in the development of nuclear weapons.

3. Apache chief Geronimo's surrender: On August 20, 1886, notorious Apache leader Geronimo surrendered to U.S. authorities in Skeleton Canyon, Arizona. Although not in New Mexico itself, Geronimo had frequently raided settlements in the state and his surrender marked the end of a long campaign to track him down.

4. First Spanish colonists arrive: In 1598, the Spanish explorer Juan de Oñate led an expedition that established the first Spanish settlement in what is now New Mexico. The settlement, called San Juan de los Caballeros, was founded on August 20 of that year and marked the beginning of Spanish colonization in the region.

5. National American Indian Day: August 20 is also recognized as National American Indian Day, which celebrates Native American cultures and contributions to the United States. New Mexico has a large population of Native Americans, including the Navajo and Pueblo peoples, and their influences can be seen in the state's art, cuisine, and traditions.