In 1931, it was officially changed to Wisconsin Dells, the name the locals and tourists had always used, with Wisconsin derived from the Native American word meaning dark rushing waters, and Dells mimicking the French word dalles that means layers of flat rock to describe the bluff rock formations.

The name "Wisconsin Dells" is derived from the French word "dalles," which translates to "slabs" or "flagstones." This term was used by early 18th-century French explorers and fur traders to describe the unique, layered sandstone rock formations that line the banks of the Wisconsin River. These towering cliffs and narrow gorges were formed over thousands of years by the rushing waters of the river carving through the soft rock. The community was originally known as Kilbourn City, but the name was officially changed to Wisconsin Dells in 1931 to better align the town's identity with the natural "Dells" that had already become a major tourist attraction. Today, while the area is the "Waterpark Capital of the World," the name remains a tribute to the geological artistry of the river that first drew visitors to this scenic part of the American Midwest.