Read May 17, 1890, before the Engineers' Club of Philadelphia.
Estimated at from 100,000 to 150,000 years. Such estimates, however, are but little better than guesses.
From the best information I can gather I am unable to decide to my own satisfaction whether or not La Salle discovered the Red River. It is not improbable that he never saw this stream, for it is more than likely that at that time, Red River poured its waters directly into the Gulf of Mexico, through Atchafalaya and Cocoudrie Bayous. That these were formerly a part of the channel of Red River, there can be no doubt. The sluggish swale that now leads from the river to the Gulf is a silted channel that was formerly large enough to carry the whole volume of Red River. Such changes in the channel of a river, when the latter flows through "made" soil, are by no means infrequent. It is only a few years since the Hoang River, "the sorrow of Han," broke through its restraining banks, and poured its flood into the Gulf of Pe-chee-lee, 350 miles distant from its former mouth.]