2022 May 16 – Calf Canyon/Hermits Peak Fire becomes largest in New Mexico history, which began in April from a prescribed burn
2014 May 21 – U.S. President Barack Obama issues an executive order creating Organ Mountains–Desert Peaks National Monument.
2012 May 23 – In New Mexico 2 lightning-sparked fires merged to form the Gila Wilderness blaze. By May 25 it had spread over 85,000 acres, or more than 130 square miles. By May 30, New Mexico’s Gila Wilderness blaze grew to over 170,000 acres, making it the biggest in state history.
2000 May 4 – A controlled burn was begun in Bandelier Nat’l. Monument. It blew out of control, destroying more than 250 homes and damaging part of the Los Alamos National Laboratory before it was controlled. The Los Alamos fire toll covered 30,000 acres with 191 housing structures burned.
1987 May 8 – U.S. President Ronald Reagan designates the Santa Fe Trail as a National Historic Trail, creating the Santa Fe National Historic Trail.
1955 May 18 – A State record 28.7 cm rain falls at Lake Maloya, NM.
1930 May 14 – U.S. President Herbert Hoover establishes Carlsbad Caverns as a National Park, elevating it from Carlsbad Caverns National Monument.
1869 May 28 – U.S. President Ulysses S. Grant appoints William Anderson Pile the seventh Governor of the Territory of New Mexico.
1865 May 9 – U.S. President Andrew Johnson proclaims the end of the American Civil War.
1861 May 24 – U.S. President Abraham Lincoln appoints Henry Connelly the fifth Governor of the Territory of New Mexico.
1853 May 6 – U.S. President Franklin Pierce appoints David Meriwether the third Governor of the Territory of New Mexico.
1848 May 30 – Mexico ratified the Treaty of Guadalupe Hidalgo. The United States acquired New Mexico, California, parts of Nevada, Utah, Arizona & Colorado in return for $15 million. This was not the last continental acquisition, however, as the Gadsden Purchase was completed in 1854.
1846 May 13 – The United States declares war on the Mexican Republic beginning the Mexican War.
1845 May 1 – José Chavéz y Castillo is appointed Gobernador de Santa Fe de Nuevo México.
1836 May 14 – Texians force captured General Santa Anna to sign the coerced Treaties of Velasco recognizing the independence of the Republic of Texas. Mexico neither acknowledges nor ratifies these treaties. Based upon these treaties, the Republic of Texas claims all land north and east of the Rio Grande del Norte to the United States border and the 45th parallel north. The Republic of Texas never occupies the region west of the 100th meridian west and this western region remains in Mexican hands. The disputed region will later become portions of the future U.S. states of New Mexico, Texas, Oklahoma, Kansas, Colorado, and Wyoming.
1836 May 2 – Texians (immigrants from the United States living in the Mexican state of Coahuila y Tejas) declare the independence of the Republic of Texas from Mexico.
1827 May – Manuel Armijo assumes office as the sixth Géfe político de Santa Fe de Nuevo México.
1760 May 10 – Don Manuel de Portillo y Urrisola is appointed Gobernador de Nuevo Méjico.
1737 May 12 – King Philip IV of Spain appoints Don Gaspar Domingo de Mendoza as Gobernador de Nuevo Méjico.
1629 May 1 – Capitán Don Francisco Manuel de Silva Nieto is inaugurated as Gobernador de Nuevo Méjico.
