The origin of the word baraboo is uncertain. Some sources say the name comes from the French rivière à la barbeau or “sturgeon river,” an early description of what is now called the Baraboo River, which ﬂows through south-central Wisconsin. Alternatively, the term may have come from Baribeau, the surname of two French brothers who owned a mill at the conﬂuence of the Baraboo and Wisconsin Rivers, or from Baribault, the name of a French trapper who had a trading post at the mouth of the river. The oval ring of hills through which the river runs also took the name Baraboo. These hills, which rise as much as 500 feet above the surrounding terrain, are made of ancient sandstone that under heat and pressure metamorphosed in the Precambrian era into extremely durable pinkish-purple quartzite—Baraboo Quartzite. The rock was subsequently covered by softer strata, which eventually were worn away by wind, water, and glacial ice, leaving the quartzite islands to stand together in early Cambrian seas—today’s Baraboo Hills. Baraboo at one point crept into geographic glossaries as a generic label for clustered hills, but this use is now regarded as antiquated and imprecise.