Fray Alonso de Posada, a Franciscan missionary, first reached New Mexico in 1651. Over the next 10 years, he ministered to the Indians of the Hopi pueblo of Awatobi and Jemez Pueblo. He also helped build the first missions of the El Paso Valley in 1659.

His performance must have pleased his clerical superiors because Posada was afterward selected to serve as head of the Franciscan Order in New Mexico from 1661 to 1665. He is most often remembered for having prohibited the Pueblos from holding their sacred kachina dances, because “they were diabolical.”

By 1686, Posada seems to have been living in retirement at the Franciscan headquarters in Mexico City. Earlier, the Spanish king had called upon the viceroy of New Spain (today’s Mexico) to gather information on the land of Quivira, allegedly located north and east of New Mexico.

Francisco Vázquez de Coronado in 1541 heard that name used at Pecos Pueblo. Quivira supposedly referred to a Native kingdom on the eastern plains where the chief, or “king,” took naps under a tree with many small bells of gold suspended from its branches. The people there commonly ate meals from plates of pure gold and silver.

Eager to discover such a treasure-laden place, Coronado marched his men as far as Kansas. But the only thing he found were Wichita Indians living in grass houses and possessing no precious metals.

However, the myth of Quivira had been launched and would remain alive for another 200 years.

Thus, when the king in the mid-1680s became interested in that visionary country thought to be within the boundaries of his empire, he told the viceroy to track down its exact whereabouts.

To accomplish that task, the viceroy assigned Posada to make a geographical study of the northern frontier. In those days, officials in Mexico City had only a vague idea of what lay north of New Mexico and Texas.

Posada proved to be a good choice. First, he was able to draw upon his own years of experience in New Mexico, during which he had often quizzed Spaniards and Indians about their travels into unknown lands outside the province.

Secondly, now resident in Mexico City, he had access to the abundant government archives. These contained journals and other papers written by explorers who had led expeditions into the heart of the continent.

Posada was aware that His Majesty had a couple of practical reasons for being interested in Quivira, quite apart from the improbable tales of its riches.

For one, the king was considering placement of a small port on the Texas Gulf coast. His advisers had told him a supply road could be opened from there, through Quivira, to New Mexico.

The purpose of the new route was to cut time and transportation costs to Santa Fe. But since no one had any idea of the actual distance across Quivira, it was left to Posada to clarify that point through his research.

A second issue that interested the monarch focused upon Diego de Peñalosa, a disgraced ex-governor of New Mexico who had fled to France. There, by claiming for himself the bogus title of the Count of Santa Fe, he gained an audience with Louis XIV.

The brazen Peñalosa raved about the gold and silver riches of Quivira. And he asked for command of a fleet of ships to go conquer that land and Santa Fe for the French.

His nutty proposal fell on deaf ears in Paris. But word of it reached Madrid and aroused the curiosity of the Spanish king. That led ultimately to Posada’s fact-finding project on the subject of Quivira.

In his final report, the padre described the rivers and mountains located in both New Mexico and Quivira. The range stretching northward from Santa Fe, that we know now as the Sangre de Cristos, he labeled the Sierra Blancas.

In addition, he included useful data on the more important Indian tribes inhabiting the study area. They included the Quivirans, numbering in the thousands, and Apaches, equally powerful, who dominated the central plains.

Posada concluded Spain should undertake the conversion of “this great multitude of Indian barbarians ... because God Our Lord will support it and provide ministers.”

He also recommended establishing the port on the Gulf and blazing from there the new trail across Quivira to Santa Fe. That didn’t happen, probably because he far underestimated the distance between the two places.

Posada’s report became buried in the archives and was long forgotten. Few scholars have made use of it, and his name seldom receives even passing mention in New Mexico history books.

That’s too bad because his document to this day contains historical nuggets of real value.

Historian Marc Simmons is author of numerous books on New Mexico and the Southwest. His column appears Saturdays.