Fritz's opinion about the source of the Amazon went unchallenged for nearly 200 years. However, in the late 19th century, the Italian-born geographer Antonio Raimondi said that Lake Lauricocha was not the real source of the Amazon, but rather the Nupe River which he said was larger and longer than the Lauricocha River. The Nupe rises from a chain of small lakes below Siula Grande, one of the highest peaks of the Huayhuash Range. Quesillococha, the uppermost lake, is located at and of elevation.