By the early 1800s, the land and streams that are now Clark County were the hunting grounds of the
Chippewa,
Dakota,
Ho-Chunk, and possibly
Menominee peoples. In 1836, these Indigenous groups were joined by a party of French-Canadian fur traders who established a temporary post for the
American Fur Company on the East Fork of the Black River. The next European-American arrivals were likely
Mormon loggers in 1844, who came to harvest pine logs from the forests along the
Black River. They floated the logs downstream to a sawmill at
Black River Falls, where the lumber was processed and transported further downriver for use in constructing the Mormon temple in
Nauvoo, Illinois. The Mormons established logging camps along the river at sites including Mormon Riffle (about a mile below Neillsville), near Weston's Rapids, and south of
Greenwood. This logging operation likely ended by 1846, when most of the Mormons left the area following the
murder of Joseph Smith. In June 1845, James and Henry O'Neill led a party overland from Black River Falls, cutting a road through the brush. They used oxen to pull a wagon carrying tools and supplies. Upon arriving, they built a cabin on O'Neill Creek, followed by a sawmill. Lumber from the mill was rafted down the Black River to Black River Falls and then transported to Alexander O'Neill in
Burlington, Iowa. However, a storm in June 1847 caused severe flooding of the Black River, destroying all the existing sawmills. Despite this setback, the settlers rebuilt. Clark County was founded in 1853 and officially organized the following year. The county's name origin is uncertain—it was either named for A. W. Clark, an early settler, or for General
George Rogers Clark. Electricity became available in some towns and villages around 1900 through private power plants. For example, in 1902, the Paulsen mill began supplying electricity to the village of Withee. However, rural farms remained without electricity until the late 1930s. In 1937, the newly formed Clark Electric Cooperative, funded by a loan from the
New Deal's
Rural Electrification Administration, began installing power lines to serve the county's rural areas. In 1920, construction began on the Clark County Asylum, located two miles east of Owen. It was the last in a network of 35 county mental hospitals established in Wisconsin, designed to provide long-term care for patients unlikely to recover. Twelve patients from the
Wausau asylum assisted with construction and became the facility’s first residents. The asylum operated a farm to keep patients engaged while supplying food for the institution. By 1924, patients cultivated 60 acres of corn, 25 acres of potatoes, 16 acres of
barley, 40 acres of oats, 6 acres of
buckwheat, and 3 acres of
millet. A dairy herd was later introduced, along with hog farming and a slaughterhouse by 1948. Over time, the institution's mission shifted from a "custodial asylum" to a "treatment hospital" and eventually to a
skilled nursing facility. Today, it is known as the Clark County Rehab and Living Center. ==Geography==