Lewis reaches the Great Falls of the Missouri; "the grandest sight I ever beheld," he writes

A year into the Corps of Discovery's march toward the Pacific, the expedition was running on hope and rumor — Native American accounts had promised a great waterfall somewhere ahead on the Missouri. In the summer of 1805, Captain Meriwether Lewis became the first white American to lay eyes on the Great Falls, describing them as "the grandest sight I ever beheld." The wonder came at a cost: the Corps spent nearly a month portaging around the cascades, an exhausting detour that deepened doubts about whether a continuous water route to the Pacific existed at all…