Topographical Map that Includes the Tributary of the Ycabaqua River, of the Negro River and the Crest that Divides Waters of the Yacuy and Uruguay until the Mountain Range of Tapes or Montegrande


This detailed Spanish map of a portion of the present-day state of Rio Grande do Sul, Brazil was prepared by Joseph Varela y Ulloa (1739-94), the commander of the Spanish party of the joint Spanish-Portuguese boundary commission that surveyed the Uruguay and Paraguay river basins between 1784 and 1788. The survey took place after the signing, in October 1777, of the first Treaty of San Ildefonso between Spain and Portugal, which settled the outstanding border disputes between the two empires in the region of the Rio de la Plata. The map includes numerous rivers and streams, settlements, missions, a fort, pictorial representation of relief, the probable track of the surveying commission, and boundary markers. Spanish and Portuguese territorial limits are recognized by color.

Date Created

Subject Date


Title in Original Language

Plano Topografico que Comprende las Vertientes del Arroyo Ycabaqua, las del Rio Negro y la Cresta que Divide Aguas al Yacuy y al Uruguay hasta la Sierra de los Tapes o Montegrande

Additional Subjects

Type of Item

Physical Description

1 pen-and-ink and watercolor manuscript map; 109 x 114 centimeters


  • Scale approximately 1:207,500

Last updated: February 9, 2012