"This cataract, long believed to be the park's tallest at 308 feet, is also one of the great waterfalls of the North America continent. It has had more words written about it than any other park waterfall. Nearly half the historic visitor reactions to Yellowstone waterfalls we collected were written about Lower Falls and its upstream campanion, Upper Falls.

A note in William Clark's journal of his famous 1802-07 expedition stated that the Yellowstone River had "a considerable fall" somewhere in the mountains. Clark then wrote "No" after it, an indication that even he did not believe what he had heard.

But the waterfall was real. Native Americans had probably seen it for years. We may never know what Euro-Americans first looked upon it, but French fur trapper Baptiste Ducharme claimed to have seen Lower Falls in 1824, 1826, and 1839. Explorers Jim Bridger and James Gemmell visited the falls in 1846. In 1851, Bridger drew a map for Father Jean DeSmet that showed "Falls 250 feet."

Traveling prospectors of the 1860s brought stories back to the Montana Territory of a huge waterfall on the Yellowstone River that appeared in frontier newspapers. One such article claimed the falls was "thousands of feet" high while another said it was 1,500 feet and called it "the most sublime spot on earth."

The 1869 Folsom expedition gave the name to both of the great Yellowstone waterfalls, from their positions on the river, and attempted to measure their heights. Their map carried the notation "Lower Falls 350 feet." However, early visitors also referred to it as the "Great Fall" or "Grand Fall" of the Yellowstone.

A notch in the riverbed causes the green color of the water that extends partway down from the top of the falls. This allows the river to retain some of its green color instead of immediately breaking into spray. In 1872 Dr. A.C. Peale mentioned this green streak was present at that time."