Black Butte was an unincorporated community in Lane County, Oregon, United States. It was located near Black Butte, a dark-colored mountain at the headwaters of the Coast Fork Willamette River, about 20 miles south of Cottage Grove, at the confluence of Garoutte Creek and the Little River. The Black Butte Mine, which operated from the 1890s to the 1960s, was one of the largest mercury mines in the state. Mercury contamination from abandoned mine tailings continues to be a health concern in the area, including mercury-contaminated runoff from Furnace Creek that has made its way to Cottage Grove Lake.