No. The longest river in Uruguay is the Rio Negro.
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Because of the river of that name that is between Uruguay and
Argentina.
But that is the River Plate, or Rio de la Plata... is there even
a river called 'the Uruguay', or Rio Uruguay?
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The Uruguay River that borders Uruguay with Argentina.
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The Uruguay River ("Río Uruguay" in Spanish) is the longest
river in Uruguay. It has 1,770 kilometers (approx. 1100 miles) of
length. It separates the country from its neighboring country
Argentina and it's from where Uruguay takes its name.