Paso Del Aguila
PASO DEL ÁGUILA. Paso Del Águila (Pass of the Eagle), on the Rio Grande in Maverick County, is a name with an interesting and somewhat complex odyssey. It was originally the name of a ford on the Río Escondido, a short distance below the site of present Piedras Negras, Coahuila, Mexico, near the site of present Villa de Fuente. The road from Presidio del Río Grande to Monclova Viejo, a military outpost on the Río San Rodrigo, crossed the Escondido at that point. Pecan, cypress, oak, and mulberry trees along the banks of the Escondido provided a nesting area for eagles, and flights of eagles to and from this site account for the origin of its name. However, just when it was so named is not known. Although Spanish exploration in this region can be traced back to the seventeenth century, the earliest record of Anglo penetration occurred in the early spring of 1834, when Dr. John Charles Beales and his Dolores colonists crossed the Escondido at this ford and found an American hunter, his wife and children, and a party of five Shawnee Indians trapping beaver. Fifty-six years before the arrival of the Dolores colonists, Fray Juan Agustín Morfi accompanied Teodoro de Croix on his tour of the northern provinces. They left Presidio del Río Grande and headed upriver toward Monclova Viejo by way of the river villages of Santo Domingo, San Nicolás, and La Navaja. On January 29, 1778, they crossed at the Escondido ford and emerged on the plain where Piedras Negras now stands. Morfi noted in his diary that the location was a fine place for a settlement and that water for irrigation could be taken from either the Rio Grande or the Río San Antonio (which empties into the Escondido two leagues from the Rio Grande).
Full article on the Texas State Historical Association's Handbook of Texas Online