Sebastian Undiano y Gastelu

Sebastián Undiano y Gastelú is credited as the author of Proyecto de traslación de las fronteras de Buenos Aires al Río Negro y Colorado, a Spanish-language work preserved in digital libraries including Project Gutenberg. The book points to an interest in the political and territorial questions of the southern frontier of Buenos Aires in the nineteenth century.

Reliable biographical information about him is very limited in the sources I could confirm. I was able to verify his authorship in library-style records, but not clear details such as his birth and death dates, broader career, or personal background.

That makes him the kind of figure readers often encounter through the text rather than the biography: an author remembered less for a well-documented life than for a surviving historical document.