Ulibarrí's diary survives and is an important source for the history of Spanish exploration of the Great Plains and relationships with the Apache and Pueblo Indians.
According to genealogical research, Ulibarrí (also known as Juan de los Reyes) was born in San Luis Potosi, Mexico and baptized there on March 8, 1670.
[1] In February 1706, New Mexican governor Francisco Cuervo y Valdés ordered Ulibarrí to explore a site in the "great forest of Doña Luisa" to determine its suitability for settlement.
In the 17th century, Pueblo frequently fled from their towns in the Rio Grande valley of New Mexico to El Cuartelejo to escape from Spanish rule and take refuge among the Apache.
[3] In 1696, Governor Diego de Vargas and Ulibarrí, who had the title of Sergeant Major, subdued the rebellious people of Taos and Picuris pueblos.
He left Taos on July 20 and headed east, crossing the Sangre de Cristo Mountains and dropping down into the upper courses of the Canadian and Cimarron rivers.
The expedition attempted to follow piles of grass made by the Apache as landmarks but became lost, finally encountering a spring and a settlement of El Cuartelejo on August 3.
[8] Ulibarrí ransomed five Pueblo Indians from the Apache by giving them a dozen horses and sent detachments to two other El Cuartelejo settlements, one of them 40 leagues (more than 100 miles away) to gather others who wished to return to New Mexico.
Among other things the Apache and Pueblos told Ulibarrí was that they had been in contact with the French on the eastern border of the Great Plains and had recently killed a Frenchman and his wife.