Drought

Great Britain’s wars with France and Spain altered the frontiers of Nueva España. During the War of Spanish Succession, the French were exploring the Mississippi river. But, by 1726 when Pedro de Rivera visited Nuevo México, they no longer were seen as a threat coming from the plains, but as one infiltrating the gulf coast. Franciscans were sent into Tejas.

México had always provoked defensive reactions from natives when new areas for mining introduced haciendas and estancias. The Santa Eulalia range near modern day Ciudad de Chihuahua was opened in 1707. Within weeks there were 15 mines. Okayh Jones estimated the population in 1725 was 2,500. Less than 20 years later, in 1742, nearly 18,000 lived there.

Expansion of the Spanish population into the north provoked new hostilities. Rivera was trying to find resources to establish a garrison where the Conchas emptied into the Río Grande from the south, when he eliminated presidio positions in Santa Fé. When Benito Crespo suggested consolidating missions in Nuevo México in 1730, it was because "for five years the fix or six missions of the north at the Junta de los Ríos, also belonging to this Custody, have been without ministers."

The needs to simultaneously defend the silver areas from hostile bands, deflect French ambitions, and protect the coast from Great Britain coincided with years of intermittent drought that began in 1735 and continued until 1744. The next three years saw more precipitation, with an El Niño in 1747. After that, wet years alternated with very dry ones in the 1750s.

Edward Cook and others at the Lamont-Doherty Earth Observatory have tried to reconstruct the western climate by analyzing tree ring records from a number of sites. They classified them by their relative wetness or dryness on a scale of 0 to 3. I’ve summarized their data in the table below to show how many sites were arid in any given year.

Year	Dry	Wet	Total	% Dry		Wars
1733	128	133	261	0.49		War of Polish Succession
1734	109	103	212	0.51
1735	275	46	321	0.86
1736	279	46	325	0.86
1737	167	111	278	0.60
1738	104	139	243	0.43		Peace Treaty
1739	169	83	252	0.67		Spain Default
1740	112	131	243	0.46		War of Austrian Succession
1741	192	58	250	0.77
1742	197	52	249	0.79
1743	148	92	240	0.62
1744	169	71	240	0.70
1745	45	221	266	0.17
1746	80	277	357	0.22
1747	39	197	236	0.17
1748	241	48	289	0.83		Peace Treaty
1749	101	142	243	0.42
1750	75	176	251	0.30
1751	84	113	197	0.43
1752	230	53	283	0.81
1753	164	70	234	0.70
1754	98	122	220	0.45		Seven Year's War
1755	148	74	222	0.67
1756	273	55	328	0.83
1757	286	22	308	0.93
1758	117	134	251	0.47
1759	135	103	238	0.57
1760	121	119	240	0.50

The greater the number of sites, given as a percentage in the right most column, the more likely it was any particular area might have been dry. I highlighted those years when 60% or more tree ring locations were arid.

In 1736, a matlazáhuatl epidemic broke out near Mexico City, where it eventually killed a third of the population, mostly natives. The outbreak, which many think was a form of typus, spread to Zacatecas the next year with travelers and migrants. It arrived during a grain shortage, which exacerbated its effects.

The infection moved north to the Pima who lived in the Santa Cruz valley between Nogales and the Gila river. Again it was taken by visitors, but this time spread for reasons specific to the efforts of Jesuits to move groups into missions.

It may or may not have reached this far north. Death usually occurred within seven days, less time than the time it took to travel from Chihuahua to Albuquerque. However, Angélico Chávez found evidence in the Santa Cruz burial records than "many children died" in October of 1737 with "no cause given." In November of that year, 38 died in Santa Fé. Another 67 were buried the following October and November.

Slave raiders in the most affected parts of México went north to replenish the labor supply destroyed by disease, arousing more hostilities in the buffer area between settlement and the southern pueblo frontier.

Apache bands, which had been pushed south earlier, coalesced into new groups that crossed the Río Grande. The Mescalero harassed the new routes east to Tejas, the Chiricahua raided in the west. The Comanche east of the Sangre de Cristo moved farther south, raiding as they went. Their hostility forced the Lipan south toward the Tejas missions. By 1747, the Utes were aggressive west of the Jémez.

Within the kingdom, the effects of adverse conditions weren’t directly recorded in documents that survived, but were reflected in requests for land grants. In 1736, five men asked the alcalde mayor of Albuquerque to permit their return to grazing lands near Isleta pueblo. They said they had left the area when the governor ordered them to, "but when they did, they found a shortage of grass."

More specific comments were made by Vicente de Armijo in 1743. He wanted to leave Santa Fé for lands near Nambé because, after several arid years,

"Having experienced innumerable sufferings and hunger and nakedness and other misfortunes in this poor kingdom on account of having lost our personal labor in our corn and wheat fields, with which we were to meet our obligations, owing to the scarcity of water in the river running through the city, which arises from the absence of rain for some time back, and our personal labor upon our grain crops being useless as they have all failed."

Rivers became unpredictable, flooding even in dry years when the surface was too parched to absorb what rain or snow did fall. In 1739, the Río Grande carved a new course around Angostura where the Santa Ana and San Felipe live today. Farther south, Francisco Silva and others petitioned for land at Tomé because they didn’t have enough land to raise crops "on account of a scarcity of water." Juan González Bas, the local alcalde, added the area was "very damp and in danger of being inundated again."

A decade later, across the river at Isleta, Carlos Delgado noted the friars were "exposed to great danger and peril at all times, having to cross rivers in canoes and often at night, and at time when their waters are in flood and very rapid."

The drought was so severe in 1752, the Río Grande was dry for its entire run though the kingdom. Then it flooded "almost every year from 1753 to 1760."

When the bishop of Durango was making his visit in 1660, the river was too high to cross at Santa Cruz in mid-June. A few weeks later, it took Pedro Tamarón’s entourage half an hour to cross the widened Río Grande from Isleta to Tomé.

The dry spell between 1755 and 1758 was accompanied by warmer temperatures. Then, winters must have become colder. In 1760, Manuel Rojo said the river froze as far south as Albuquerque. "When the ice thundered, he thought he was on the way to the bottom, because when one crosses it, it creaks as if it were about to break."

Notes: The five men near Isleta were probably Pedro Barela, José Sanches, Antonio Lucero, Juan García, and Jacinto Barela. On 30 January 1736 they were "asking permission to remain with their herds." The progenitors of Juan González Bas lived in La Cañada before the Revolt. He was discussed in the post for 19 March and 7 April 2014. Twitchell identified him as Juan Griego Bas. Crespo’s suggested reforms were described in the post for 28 June 2015.

Adams, Eleanor B. Bishop Tamarón’s Visitation of New Mexico, 1760, 1954.

Armijo, Vicente de. Petition, 1739; translation in Twitchell, volume 1.

Baxter, John O. Las Carneradas, 1987; on petition for grant near Isleta.

Chávez, Angélico. Archives of the Archdiocese of Santa Fe, 1678-1900, 1957.

Cook, E. R., D. M. Meko, and C. W. Stockton. "U.S. Drought Area Index Reconstruction," 1998, from the International Tree-Ring Data Bank, Boulder, Colorado.

Crespo y Monroy, Benito. Letter to the viceroy, Juan Vásquez de Acuña, 8 September 1730; translation in Adams; recommended consolidating missions.

Delgado, Carlos. Report to our Reverend Father Ximeno concerning the abominable hostilities and tyrannies of the governors and alcaldes mayores toward the Indians, to the consternation of the custodia, 1750; in Adolph F. A. Bandelier and Fanny R. Bandelier, Historical Documents Relating to New Mexico, Nueva Vizcaya, and Approaches Thereto, to 1773, volume 3, 1937, translated and edited by Charles Wilson Hackett.

Dobyns, Henry F. Tubac through the Centuries, 15 March 1959.

Ellis, Florence Hawley "Tomé and Father J. B. R.," New Mexico Historical Review 30:89-114:1955; quotation by González Bas cited by Scurlock.

Jones, Okayh L. Junior. Nueva Vizcaya, 1988. The population in Saint Eulalia in 1725 was 214 vecinos; 292 vecinos were in San Felipe, now Ciudad de Chihuahua. He multiplied their totals by 5 to estimate the population.

Raigoza Quiñónez, José Luis. "Factores de Influencia para la Transmisión y Difusión del Matlazáhuatl en Zacatecas 1737-38," Scripta Nova, August 2006.

Rivera, Pedro de. Report to the Oidor de Guerra, 1726, in José Antonio Pichardo manuscript, 1808-1812, translated and annotated by Charles Wilson Hackett in Pichardo’s Treatise of the Limits of Louisiana and Texas, volume 1, 1931.

Scurlock, Dan. From the Rio to the Sierra: An Environmental History of the Middle Rio Grande Basin, 1998; on floods in 1750s.

Tamarón y Romeral, Pedro. The Kingdom of New Mexico, 1760, translation in Adams. He began his stay at Albuquerque on May 20, at Santa Cruz on June 14, and at Isleta on July 3.

Twitchell, Ralph Emerson. Spanish Archives of New Mexico, two volumes, 1914; quotations about Varela petition and Tomé in volume 1.

Table: Precipitation data for western United States from Cook. Each site was rated on a scale of 0 to 3. Dry, Wet and Total columns are the total number of points with negative (dry) or positive (wet) readings. Years with at least 60% of their areas dry are in boldface.