Ioday in the Northwest, some people are fascinated by rumors of the wild, ape-like beast known as Sasquatch. Others like to tease tourists with tall tales of jackalopes and side-hill gougers. To Thomas Jefferson and his contemporaries, Louisiana Territory was full of possibilities, some conceivably real, others absurdy fictional. The President suspected that in addition to a water route to the Pacific Ocean, it might contain a species of giant ground sloth (which he called a "megalony"X). More fanciful gossipers announced that somewhere out there was an immense lake of molasses, an extensive vale of hasty pudding, and prairies of soil too rich to grow trees.
Considered among the most plausible projections by thoughtful people at the time was a lost tribe of Welshmen, and a mountain made of salt. President Jefferson explained the latter to Congress. "There exists," he said, "about 1000 miles up the Missouri, and not far from that river, a salt mountain! The existence of such a mountain might well be questioned, were it not for the testimony of several respectable and enterprising traders who have visited it, and who have exhibited several bushels of the salt to the curiosity of the people of St. Louis, where some of it still remains. . . . This mountain is said to be 180 miles long, and 45 in width, composed of solid rock salt, without any trees or even shrubs on it."1
Jefferson refrained from mentioning it in his instructions to Meriwether Lewis, and all the journals are mute on the subject.
1. Account of Louisiana, being an abstract of documents delivered in, or transmitted to, Mr. Jefferson, President of the United States of America and by him laid before Congress, and Published by Their Order. Printed at Washington, and reprinted at Philadelphia, and all the other States of the Union. (London: Reprinted for John Hatchard,...1804).